Rodolfo Amedeo Lanciani.

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yet leave the apparent bipartite unit undisturbed in internal
relations.

Antero-posterwritu exhibits the same interchangeability as
bilaterality, but, although plainly enough, not so conspicuously
in a comparative, homological sense as in the ph^iologicaJ
interplay of the functions, such as we see in the relations of the
allantois to respiration in the embryo, or in the ratio of excretion
of the renal organs dependent upon the degree of activity of
the respiratory and perspiratory mnctions ; or in the relation of
the reproduclJve organs to the vocal and respiratory, when the
former are in an abnormal condition, or when they change from
one period of life to another, from youth to adolescence ; and
in many other interdependent relations fiuniliar to the mor-
phologist of the present day.

Bilaterality, antero-posteriority, anddorso-ventrality, the three
principal sxwdominants of polarity^ have a very methodical dis-
position, and are quite pronounced and sharply defined among
the higher groups of animals, — ^the more seemingly units of
organization, — but if we ffo to the opposite extreme of grade
we shall find, among the lower classes of life, that the polaric
element (like the diflerentiation of organization, and tnat of
function) is in an almost elementary condition, expressing itself
vaguely in the scattered heads of a branch of Coryne, or Tu-
bularia, or Clavellina; or a little more determinately in the
distichous arrangement of the hydra heads of Dynamena and
Sertularia, or in the singularly stellate disposition of the zooids
of Botryllus, with their common cloacal orifice.



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72 H, J. Clark on Polarity and PolycephcdimL

When, however, polymerism, in its usually accepted sense,
fidls, as it does step by step in the gradually rising degrees of
rank, polarity gains the ascendency in point of regularity and
the closer intimacy and symmetrical arrangement of the com-
ponents of the organization which it holds sway over. Thus
it is that two, or more, scattered, consimilar parts, or comjdete
organizations may combine to form a seeming owe, an apparent,
bipartite or multipartite unit The multiple repetiti<Jli oi heads
among the lower polymeric kinds is here reauced to a dual
repetition, and the parts condensed into one form an approxi-
mative unit, a zoological individuum, as the highest expression
of unity attainable by the vertebrate zoon.

The duality, nay tne plurality of the subdivision of the ver-
tebrate axis, as illustrated by the embryo fishes of Lereboullet,
is recalled in the diffuseness of the many hydrse of the den-
dritic Campanulariae, or disguises itself under the interminable
heteromorphism of the Siphonophorae ; it is polymerous but
dimorphous in Salpa, or polymerous but monomorphous in the
fresh water Polyzoa ; temporarily a poljrmerous, monomorphic
individuum in the fissigemmating Hydra, it eventually resolves
itself into disconnected o5et«fo-i^ttn(itwi; for a time polymer-
ous but dimorphic in the annelidan Myiianida of Milne-Ed-
wards it finally assumes the appearance of a true, self-contained
individuum in each one of the separate, independently moving
sexual segments, and in the original budding-stock (the direct
legitimate oflFspring of the egg) from which they shot fortL

The thorough historian of the multifarious, so-called alternate,
generations of the Acalephas will see nothing but a generative
organ in the spermatic and ovarian sacs of Hydra ; and detect
nothing more in the grape-like clusters about the base of the
head of Clava, or in the grouped momliform projections behind
the corona of tentacles of Eudendrium. The polymerism of these
or^ms of Eudendrium is merely, and nothing more than a re-
petition of the simple sac of Clava ; the diversity in form is
only apparent But one step higher in complicity and our ob-
server will find in the tentaculiferous terminations of the repro-
ductive sacs of Thamnocnidia and Parypha a premonition of a
forthcoming cephalic independence, such as is already fully
exemplified in the many hydras of the polymeric, dendritic
mass. A similar progression toward cephalic freedom will also
be seen in the simplest generative sacs of Laomedea amphora,
and L. flexuosa, ic., and rising through successive degrees of
complicity to those of Gonothyrea ^jaomedea) Lovenii All,
which not only are tipped with tentaculate processes as in Pary-
pha and Thamnocnidia, but have developed within them a
series of longitudinal tubes, like those in the homologous organ
of Tubularia indivisa.



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H. J. Olark on Polarity and Polycephalism. 73

Gradually and methodically tlie progressive steps of com-
plication lead on, with a more and more marked separation of
the genitalia from a direct relation to the general mass, or even
to the hydr» in particular, whilst a consentaneous development
gathers around tnem and brings them into immediate alliance
with an envelope whose morph is only a slightly varied repeti-
tion of that of the hydra, but whose greater d^ree of com-
plicity gives it a better claim to be ranked as the highest
among the cephalic subdivisions of the body. But the fall aim
of the train of development is not divulged here ; its results
only exemplify, a part of it in the predominance of the repro-
ductive function and a differentiation of the nutritive cavity
into distinct channels of circulation, and the subordination of
a definite r^on of its periphery to a tentacular, prehensile
offica

Step by step, however, all the elements of a complete organ-
ism are successively absorbed out of the primitive hydra-mass,
and remodelled into the fashion of a meausoid ; the reproduc-
tive character has become a less obtrusive feature ; motion at-
tracts attention above all others ; prehension has fiiU sway in
the highlv developed tentacles ; and the latter point, like fin-
gers, to the self-sustaining power of the acalephan morph in the
complete organization of the longitudinal and circular chymife-
rous channels, opening into the receptive cavity of a highly flexi-
ble, proboscidal rnanvbriuTn, The preliminary processes of fissi-
gemmation are complete ; the primary genesis of the ovuniy in
its integrity, is finished ; the primitive stock has become differ-
entiated into two widely diverse varieties of one morph, the
hydroid cephalism and the Tnedtisoid cephalism. Such is the con-
dition at which the hydromedusariae of Corymorpha, Hyboco-
don, Ectopleura (Tubularia) Dumortierii, Pennaria, Coryne mi-
rabilis, Margelis, Bougainvillea, and many Campanulanae have
arrived previous to the disintegration of their mass into the
free pseudo-individual medusoids, and their less independent,
contemporary homologues, the persistent hydroid cephaiisms.

No one holding the present prevailing views in regard to in-
dividuality would find a diflSculty in seeing that the members
of a chain of Salpse are so-called individrmls, notwithstanding
they are attached obliquely end to end, and organically con-
nected. Now although the self-dividing worm, Myrianida for
example, the so-called asexual stock maj become, by actual
separation, two individuals, apparently, viz : sexless and sexual,
yet once they were more closely connected organically than the
Salpae which do not separate. Is now the closer connection of
the yet unseparated asexual and sexual parts of the worm to
make them less distinct individuals than those of the Salpa ?
It would seem so, according to the advocates of individualism ;



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74 H. J. Clark on Polarity arid Polycephalism,

and therefore the Myrianida, with its posterior string of six or
seven consecutive sexual buds is a monocephalic individual.
But in the sexless Salpa-form budding the sexual chain we
have a closer parallelism with the worm than in the chain
alone, in fact an identity of relation ; and vet for all that we
would not think of calling the stock (sexlessj and the chain
(sexual) together one individual, with one nead, but rather
many head^, or in other words a polyTneric unit or individual^
of sexual and sexless cephalisms. Therefore by a parity of
reasoning we ought to denominate the Myrianida and its buds
as a succession or series of cephalisms. The fact that the worm
components are more in one line than in the Salpa only makes
an apparently more individualistic body. Among tapeworms
the several heads {cephahids) of the scoUx (Coenurus) of Taenia
Coenurus are not arranged in a line end to end, but all are free
anteriorly, and connected with each other posteriorly by a
common body. The closer connection of the subdivisions of
the annelid is only one of degree ; and as to having more organs
in common than the Salpa it is rather like the community of
interest which the coral cephalisms have in the main trunk.

Since the sexual and sexless are necessarv to make up a
complete organism, i. e., vegetative and reproductive, the one
a completement of the other, neither aUme can represent the
individual unit, or whole cycle of life : and Cephalism there-
fore is a better term to indicate the potentiality of these sub-
divisions to live apart, although it does not always occur (as in
Corals, Bryozoa, some Campanularise and Tubulariae), or when
apart (as in other Tubulariae [T. Dumortierii], Laomedece [Eu-
cope diaphana, &c.,] and Saluse, Myrianida, &c.,) meaning more
or less incomplete individuals (pseudo-individuals) which are
either mainly vegetative or mainly reproductive, as the case
may be.

We look upon cephalism then, on one hand, as having a con-
trolling influence of a low degree of independence when shared
in common by the multiple heads of a coral polypidom, and, on
the other hand, as attainmg to the highest independence as a
controlling j)ower, when the multiple parts of a so-called com-

Sound individual separate from each other, and are singly un-
er the influence of this power. The latter obtains when Hy-
dra or Actinia separates its buds from itself ; or when the sex-
ual part of the annelid worm subdivides from the asexual one.
Cephalism of a low degree is more readily recognized in the
aggregated cephaloids of Salpa than in the undivided worm,
but, unlike the latter, remain connected cephaloids (in the
chain) when separated from the budding stock.

By thus dividing the body of a Hydromedusa into two parts,
which shall contain, severally, the vegetative dominant (i e.,



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T, & Hunt on Lcmrention Rocks in Jfassachusetts. 76

vegeiaiive cephdbid) and the sexual dominant, {%. e., sexual ceph-
ahid) we avoid the absurdity of assigning individuality to the
egg-sac of Hydra and others of its allies which have evidently
a mere genital organ. Although we might be inclined to
admit that some cephalisms may gradually become complete
individuals, as when the buds of Actinia or Hydra separate
fifom the parent body ; on the other hand we must insist that
an mdiviaual cannot retain the same significance when reduced
to a mere genital orga/n, as when, in Coryne, a free medusoid
(Sarsia) later in the season becomes an ^g-sac ; or the free
medusa of Tubularia (Ectopleura') Dumortierii is represented in
Tubularia (Thamnocnidia) spectaoilis and Parypha crocea bv a
plain sac ; or in SiphonophorsB where a subdivision may be either
a sexual medusoid, or a sexless swimming-bell, or a mere
^^scale."

Under the term cephaiism we include two forms, or morphs,
viz : (1^ the cephcdidy or such subdivisions of a body as have
a complete organization, whether united in common (as in some
Vorticellidae, Corals, Bryozoa, Crinoid», some Ascidiadae, and
Pyrosomidse^ or separatmg singly from the main stock (as in
^dra and Actiniae), and (2) me cephaloidy or those divisions
01 a fissigemmating body which do not contain a complete
organization, and may be either mostly sexual (as the so-called
medusa of Hydromedusee, or the posterior divisions of Myri-
anida and other worms, or the jointa of Taenia, or the Cerca-
riae brood of Distoma, or the chain of Salpa) or mostly v^eta-
tive and sexless (as the hjdra of Hydromedusae, the Myrianida
stock, the head of Taenia, the single, budding stock of Salpa
or the budding Cercaria-nurses of Distoma.)



Abt. X. — On Laurentian Rocks in Eastern Massachusetts; by
Dr. T. Sterry Hunt^ F.RS.

In a paper read before the American Association for the
Advancement of Science at Washington in April, 1854, and
published in this Journal for September in the same year, (vol
xvii, page 198,) I noticed the crystalline limestones of north-
eastern Massacnusetts, which were described by the late Dr.
Hitchcock as enclosed in the great gneissic and homblendic form
ation stretching through that portion of the state. These lime
stones, which are met with at various points fix)m Bolton by
Chelmsford on to Newburyport, present a close mineralogical
resemblance to those of the Adirondacks and Laurentides, and
also to those of the Highlands of New York and New Jersey,
a resemblance which extends to the gneissic rocks which m



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76 T, S, Hunt on Laurentian Bocks in MasscuJiusetts.

these various regions accompany the crystalline limestones, I,
at that time, accepted without examination the view maintained
by Mather and H. D. Eogers, that these limestones in southern
if ew York and New Jersey were altered Silurian strata, al-
though mineralogically identical with those farther north of
undoubted Laurentian age. Led by this conclusion to attach
comparatively little importance to mineralogical and lithologi-
cal resemblances, and guided by other considerations given in
the paper just referred to, I then suggested that the crystalline
limestones and their accompanying rocks in northeastern Massa-
chusetts might probably be of Devonian age. The subsequent
investigations of Hall, Logan and Cooke in the Highlands of
New York and New Jersey have however left no doubt that
these supposed altered Silurian rocks are really of Laurentian
age, and led me to suspect that the same might be the case
with those of eastern Massachusetts. This view, which was
shared by Prof. James Hall, I ventured to put forward at the
meeting of the American Association for tne Advancement of
Science at Salem in August, 1869, when I showed that it was
probable, not only on lithological grounds, but from the fact
that the Laurentian rocks appear to the southward of the great
paleozoic basin in New Brunswick and Newfoundland, wnich
are geologically but a northeastern prolongation of New Eng-
land, and moreover from the outcropping of the lowest Silu-
rian strata at Braintree near Boston. A few days later I visited
Newburyport, and in company with Dr. Henry C. Perkins of
that place, had, for the first time, an opportunity of observing
the gneisses and limestones in (question. Their aspect confirmed
my suspicion of their Laurentian age, and led me to suggest to
him the propriety of searching for JEozoon Oanadense m the
limestones wnich there occurs mingled with serpentine. Speci-
mens of it were thereupon placea in the hands of Mr. Bick-
nell of Salem, well known as a skilled microscopist, and shortly
after it was announced by Dr. Perkins that Mr. Bicknell had.
discovered in them the Eo25oon. This notice, which appeared
in September in a Newburyport journal, is reproduced m the
American Naturalist for November. My own specimens col-
lected in August last near Newburyport, at the locality known
as the Devil's Den, did not however furnish any traces of Eo-
zoon, and I may here remark that I had already, so long ago
as 1864, caused slices to be made of a specimen of limestone
from that locality, which were then examined by Dr. Dawson
with negative results. In November, however, Mr. Bicknell
visited Newbuiyport and got fi^m a quarry about a quarter of
a mile distant trom the place just mentioned, specimens of a
serpentinic limestone in which he again found Eozoon. Slic^



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T, & Hunt an Laurentia/n Bocks in Massachusetts. 77

which he has kindlv sent me have also been examined by Dr.
Dawson, who connnns Mr. Bickneirs observation, and finds
in them Eozoon Canadense^ though fragmentary and not very
well preserved. The tubuli, as in the specimens fix)m Gren-
ville, are injected with serpentine, and may be seen on etched
surfsBu^es as well as in transparent slices. A crystalline mineral
is however abundantly disseminated in the limestone, and un-
skilled observers might have difficulty in recognizing the fossil
Another locality, about twenty-eight miles to the southwest-
ward of Newburyport, has however afforded me much better
specimens. In company with Mr. L. S. Burbank of Lowell, a
zealous and successful teacher of geology and mineralogy, I
visited in October last, the limestone quarries of Chelmsford,
some five miles from LowelL This limestone and its accom-
panying gneiss closely resemble the Laurentian rocks of other
r^ons, and scapolite, apatite and serpentine occur as associ-
ated minerals, though the latter was rare in the quarries then
visited. A few days afterward Mr. Burbank kindly sent me
specimens of a mixture of limestone and yellowish-green ser-
pentine from another quarry in the vicinity, which I had been
unable to visit, and these nave proved to be rich in Eozoon
Canadense. The continuous and complete calcareous skeleton
of the fossil does not appear in these specimens, which seem
like some portions of the rock from Grenville, as described by
Sir W. E. Jjogan, to be made up of fitigments of the calcareous
shell of Eozoon, mingled with grains of serpentine, and cemented
by crystalline carbonate of lime. In the specimens fix)m Gren-
ville, and from most other localities, the mineral matter replacing
the sarcode and filling up the canals and tubuli in the calca-
reous Eozoon skeleton, is generally serpentine or some other
silicate. Both Dawson and Carpenter however, it will be recol-
lected, found that in the fragmentary Eozoon from Madoc, and
in some small portions from Grenvifle, the injected mineral was
Uke the shell itself, pure carbonate of lime, though readily dis-
tinguishable by differences in texture and transparency from
the shell Such is also the case with all the Chelmsford speci-
mens yet examined, which abound in fragments of shell exhibit-
ing in a very beautiful manner the cylmdrical diverging and
branching tubuli The accompanying serpentine is disseminated
in grains, but has no connection with the organic forms, so that,
unSke the specimens in which it is the injecting mineral, the
stnicture of these cannot be brought out bv etehmg with acids.
These specimens from Chelmsford, it should be said, have
been examined and satisfactorily identified by Dr. Dawson.
The argument from, mineralogical and lithological resemblances
in favor of the Laurentian age of the limestone in question is
therefore now supported by tne undoubted presence in them of



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78 C. A, Ooessmann on the Chemistry of Chmmon ScdL

Eozoon Canadense, In this connectioii it should be said that
the crystalline rocks of Newburyport and Salisbury, though
separated in Hitchcock's geological map from the gneisses to the
southwest, and united to the syenites of Gloucester and Rock-

Eort, seem to me very unlike the latter, and closely related
thologicall y to the gneiss of Chelmsford, which encloses the
crystalline limestone. The crystalline limestones occurring
with eneissic rocks near Providence, Ehode Island, merit a
careful examination for Eozoon, inasmuch as from their litho-
logical characters they may with probability be supposed to be
of Laurentian aga

Montreal, Dea 13, 1869.



Art. XL — Cbntrtbutions to the Chemistry of Common Salt: toith
particular reference to our home resources ;* by C. A. GoESS-
MANN, Ph.D., Professor of Chemistry, Massachusetts Agri-
cultural College, Amherst

However chemists and geologists may differ in regard to
the methods by which chlorid of sodium has accumulated in
the course of time within the waters of the ocean, there is at
present but little dissent fix)m the opinion, that the ocean has
at all times been charged with salt, and that the saline residues
of the oceanic waters of former geological periods, together
with those of the present day, furnish us with our natural
sources of supply.

The salt of commerce is chlorid of sodium more or less con-
taminated with various saline admixtures. These foreign sub-
stances may differ in quality or qumitity. The differences in
the kind of the foreign admixtures are due to the peculiarities
of the source used for the manufacture. The differences in the
quantity of the impurities, so far as the same kind of saline
compounds is concerned, are determined not only by the con-
dition of the source, but also by the mode of manufacture and
by the amount of care bestowed upon the working. The fitness
of a salt for domestic and industrial purposes depends quite fre-
quently not less on its mechanical condition, than on its chemical
purity ; and as the composition of its natural as well as its artifi-
cial solutions exerts a most decided influence on both, it seems
but proper that I should briefly consider the chief foreign saline
compounds usually associated with the chlorid of sodium. To
do tms, we must go back to the primitive condition of our planet

Accepting the theory that our earth has grietdually passed

* Read before the National Academy of Sdenoe at its Northampton meeting)
August, 1869.



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C. A. Ooessmann on the Chemistry of Common SaU. 79

bom a gaseous to a solid condition, we may assume that the
formation of chlorid of sodium took place mainly during the
last stages of its consolidation, at a period when the more
volatile elements reacted upon each other, in consequence
of the diminution of temperature ; that subsequently water
caused the oxydation of numerous chlorids and sulphids,
the acids of sulphur and of chlorine which thence resulted
acting upon the solidified surface of the new planet ; and, that
finally these more or less violent physical and chemical revolu-
tions resulted in the formation of the primitive ocean.

A more prolific field for speculation concerning the kind, the
extent, and the order of succession of the chemical reactions,
which may have preceded or accompanied the formation of
this first ocean, cannot readily be conceived, since more com-
plicated relations of matter and force can scarcely be presented
for investigation. Speculations upon the last stages of the
chaos, therefore, are very likely to lead us into a chaos of
chemistry ; for — to point out but one circumstance — ^the very
important question a3 to the relative intensity of the various
chemical agencies which may have been in action at any riven
point, is, and will always be, a mere matter of conjecture. Inas-
much as all our knowledge concerning chemical affinity, has
been obtained by experimenting, under well defined conditions
and on a comparatively very limited scale, it is evident that the
application even of well established chemical laws to the deter-
mination of the violent reactions of the atmospheric agencies
of that period upon the solid crust of our earth, should be
made with caution. We are not without ingenious statements
concerning the chemistry of that stage of our planet's history ;
yet, as their details in many instances are and always will be
subiects of controversy, I deem it advisable to give merely an
outline of those probable chemical and physical changes which
bear directly upon the question here under discussion.

Taking into consideration the peculiar constitution of primi-
tive rocks, their present surface condition, and the predonunance
in them of silicic acid, in connection with the probable character
of the primitive atmosphere, there appears to be some force in
the suggestion, that the decomposition of the silicates of iron,
of alumina, of lime, of magnesia, of potassa, and of soda, by
means of sulphuric acid, and particidarly of hydrochloric acid,
may have famished the salme constituents of this primitive
ocean. The compounds resulting from this chemical action
being soluble in water, at least in part, were continually carried
away in solution and accumulated finally in lakes and oceans.
The chemical composition of those oceanic waters was depend-
ent, therefore, on tne nature and the extent of the surface disin-
t^ration, the concentration as well as the relative proportion of



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80 C A. Goessmann an the Chemistry of Common Salt

their saline constituents being very different from that found at



Online LibraryRodolfo Amedeo LancianiThe American journal of science and arts → online text (page 10 of 109)