follows.
198 PHYLUM IV. SIPHONOPHYCEAE
(.s) INIoimt carefully a considerable portion of a fresh plant,
and examine its structure under a low power. Note that in
some species the stem is composed of a row of large coenocytes
surrounded by a coat of smaller ones. Look for the rapid
movement of protoplasm which is so marked in these plants.
(0 Mount several spore-fruits in various stages of develop-
ment. Note the covering layer of spirally coiled cells surround-
ing the oogone (in young specimens) or the resting spore (in
older specimens).
(u) Mount several full-grown compound antherids. Care-
fully crush them and look for sperms, which are produced in
chains of cells (antherids).
LITERATURE OF SIPHONOPHYCEAE
Frank S. Collins, The Green Algae of North America, Tufts
College, 1909.
G. S. West, A Treatise on the British Fresh-water Algae, Cam-
bridge, 1904.
F. E. Clements, The Genera of Fungi, Minneapolis, 1909.
W. Migula, Die Characeen, etc., in Rabenhorst's Kryptoga-
men Flora von Deutschland, Oesterreich u. d. Schweiz, Vol. V,
Leipzig, 1897.
CHAPTER XI
PHYLUM V. PHAEOPHYCEAE
THE BROWN ALGAE
301. The Brown Algae which are almost wholly marine
plants of shallow waters, numbering about 1000 species,
are all truly cellular, and range from small filamentous
few celled plants, to large massive organisms differenti-
ated into roots, stems and leaves. They are brown-
green in color, and contain other coloring matters in their
cells in addition to chlorophyll. They are propagated
mostly by laterally biciliated zoospores, and generated
in the lower families by isogametes, and in the higher
famiUes by heterogametes, their union in all cases pro-
ducing a simple zygote. The gradations in the sexual
union of the gametes include (1) biciliated isogametes,
(2) biciliated heterogametes, (3) biciliated for uniciliated)
sperms and non-ciliated eggs.
302. In this phjdum the dominant feature is the addi-
tion of the brown pigment, phycophaein, to the chloro-
phyll of the cells. With this character must be associated
the typically motile, usually biciliated gametes, produc-
ing simple zygotes upon uniting, and the rooted plant
body (from filamentous and small, to massive and
large.)
303. Brown Algae probably originated in the vicinity
of Ulotrichaceae in the Chlorophyceae. The phylum
constitutes a ''side line" diverging from the main evolu-
tionary stem or current.
199
200 PHYLU:M \. PHAEOPHYCEAE
304. Among the commonest of the smaller Brown Algae
are the species of Ectocarpus in which the plant body is
composed of simple or branched filaments which may
attain a length of many centimeters. They
are firmly rooted below, and their tufted
filaments float as dark brown masses in the
tide currents near the shore. They are
propagated by zoospores produced in one-
celled sporangia which occur on the sides
Ectocafpus. of the filaments. These zoospores are
oval, pointed anteriorly, and have two
long cilia which are attached near together at one side.
Generation takes place by the union of isogametes, re-
sembling the zoospores, but originating in many-celled
sporangia (gametangia) also occurring on the sides of the
filaments. This union takes place in the water after
both gametes have escaped from the sporangia, and it
results in the formation of a zygote, which soon germi-
nates and gives rise to a new plant.
305. The Kelps (Laminariaceoe) while large massive
plants are still of a low type. In the Flat Kelps, or
Devil's Aprons (Laminaria), there is a stout stem a cen-
timeter or so thick, and a decimeter to nearly a meter
long, firmly rooted below, and flat-
tened into a broad 'Ueaf" above.
The whole plant may be a meter or
even several meters in length, and
the ''leaf" a few centimeters to half
a meter in breadth. On the sur-
face of the ''leaf" there develop """• s^-^-^^-^"-
patches of 1-celled sporangia that produce zoospores
like those in Ectocarpus. Gametes are not certainly
known to occur in the Kelps.
306. Other kelps that are common on the Atlantic or
KELPS 201
Pacific coasts are the Sea Girdle (Cymathere) with a
narrow beautifully ribbed " leaf" ; the Sea Tree (Lessonia)
with a stout branching stem bearing many small leaves;
the Sea Palm (Postelsia) with an unbranched stem bearing
a tuft of leaves at the top; the Bladder Kelp (Nereocystis)
with a long, cord-like stem, often 10 to 15 meters long and
bearing an air bladder at the top, to which is attached a
tuft of large leaves; the Giant Kelp (Macrocystis) with a
long, slender, cord-like stem, sometimes 50 to 75 meters
long and bearing a row of large leaves toward its extrem-
ity, each with a basal air bladder; the Leafy Kelp (Egre-
gia) with a fiat stem which bears innumerable lateral leaf-
lets and air bladders.
307. The highest of the Brown Seaweeds are the Rock-
weeds and Gulf weeds (Fucales) in which the plant body is
of medium size (usually from a decimeter
to a meter in length), rooted below, and
massive and branching above. Their
tissues, too, show a considerable differ-
entiation; the cells are arranged in cell-
masses, and these are differentiated into
several varieties of parenchyma, and other
tissues approaching, in some instances, to the condition
which prevails in higher plants. Some species develop
air bladders in their tissues.
308. With the foregoing there is found a marked differ-
entiation of portions of the plant ])ody into general re-
productive organs, analogous to the floral branches of
higher plants. The sexual organs are developed upon
modified l^ranches, which differ more or less in shape and
appearance from those destitute of such organs.
309. In all Rockweeds the asexual reproduction
("propagation") has been suppressed, the emphasis l^eing
placed upon the sexual reproduction ("generation").
Fig. S7. — Fucus.
202 PHYLUM V. PHAEOPHYCEAE
310. In common Rockweeds (Fucus) of the seashore
the sexual organs are found in the thickened ends of the
lateral branches. The}^ occur on the walls of cavities
(conceptacles), which are spherical, with a small opening
at the top. The conceptacles are at first portions of the
general surface, and afterward become depressed and
walled in by the overgrowth of the surrounding tissues;
they are thus in reality portions of the general surface.
311. The walls of the conceptacles are clothed with
pointed hairs, which in some species project through the
opening, and among these are found the sexual organs.
The antherids are produced as lateral ])ranches of hairs;
each antherid is a thin-walled structure containing a
large number of biciliatecl sperms, which escape by the
rupture of the surrounding wall. Before rupturing,
however, the antherids detach themselves and float in the
water with their contained sperms.
312. The oogone is a globular or ovoid short-stalked
body containing eight eggs. These escape from the
oogone and float out through the opening of the concep-
tacle, into the open water. The sperms, which are lib-
erated at about the same time, gather around the
inactive eggs in great numbers, and by the vigor of
their movements sometimes actually give them a rotary
motion. Fertilization results from the union of one of
these sperms with the egg, the zygote thus produced
secreting a Avail of cellulose about itself.
313. In germination the zj-gote lengthens and under-
goes division into numerous cells; at the same time it
elongates below into root-like processes, which serve to
hold fast the new plant.
314. In the nearly related Gulfweeds (Sargassum) the
plant body is composed of a distinct stem, rooted below,
and bearing leaves above. The stem bears also many
GULFWEEDS 203
stalked air bladders which ])uoy up the plant when
rooted, and float it when torn free. The short, thickened,
elontrated and clustered axillary branches (receptacles)
which contain the conceptacles ma}' be dis-
tinguished easil}^ from the spherical air l^lad-
ders. There are many species, one of which
(Sargassum vulgare) is common along our
eastern coast as a low-tide plant, half a meter
to a meter long. Another smaller species Fig. 88.
/-» •/• \ n • '111 Sargassum.
{bargassum oacciferum) iloats m considerable
quantities in the so-called ''Sargasso Sea" of the central
Atlantic Ocean. Its proper home is in the West Indian
region, where it grows attached to rocks.
Laboratory Studies. Probably the best Brown Algae for the
beginner to take up are Ectocarpus, Laminaria, and Fucus.
(a) Good material of Ectocarpus for study may be obtained
of dealers in laboratory supplies. The specimens should be
examined with reference to tlic general form and appearance of
the plant body, and especially for the 1-celled, and the many-
celled sporangia.
(/;) Where fresh material cannot be secured, the Kelps may
be studied very well from preserved specimens, which can also
be obtained from dealers in botanical supplies.
(c) Study the tissues of Laminaria and other Kelps in cross
and longitudinal sections.
(d) Make sections through the fruiting j)atc]ies and examine
the sporangia and ''paraphyses," that is, the elongated,
intervening protective cells.
(e) It is helpful to have jars of other Kelps, as Sea Palms,
Bladder Kelj)s, Giant Kelps, Leafy Kelps, etc., for macroscopic
observation.
(/) Secure specimens of Rockweeds, fresh, alcoholic, or dry.
Fresh ones may easily be found along the beach of the ocean
after a storm. AlcohoHc and dry specimens and even living
material can easily be procured by purcliase or exclianpe.
Make thin cross-sections through the conceptacles in the thick-
ened ends of the branchlets. When mounted in water, even the
204 PHYLUIM V. PHAEOPHYCEAE
sections from the drj" specimens will frequently show the sexual
organs quite well. It must be remembered that some species
are dioecious, i.e. have the antherids on one plant and the
oogones on another.
(g) Make very thin cross and longitudinal sections of differ-
ent portions of the plant bod}', and study the tissues. Note
particularly the boundary tissue (epidermis), and the cells
constituting the mid-ribs and harder portions of the stems and
leaves.
(h) Secure in like manner specimens of Gulfwced, and make
macroscopic examination of the plant body, then if there is
time available make cross-sections of the air bladders and the
receptacles.
LITERATURE OF PHAEOPHYCEAE
George Murray, An Introduction to the Study of Seaweeds,
London, 1895.
G. B. De Toni, Sylloge Algarum, vol. Ill, Padua, 1895.
W. G. Farlow, Marine Algae of New England and Adjacent
Coast, Washington, 1881.
CHAPTER XII
PHYLUM VI. RHODOPHYCEAE
THE RED ALGAE
315. The Red Algae are almost wholly marine plants,
in structure ranging from small, simple, cellular, attached
filaments to stout, massive, rooted plants which may
attain considerable dimensions (half a meter or more).
The smaller plants are often diffusely and beautifully
branched into quite intricate patterns, rising from a
short basal stem which is rooted below, while in the
larger forms there may be a thick, rooted stem
which bears one or more flat leaves above.
316. The cell walls of the Red Algae are
more or less gelatinous in nature and swell
greatly in fresh water, even dissolving. The
cells usually are connected with one another
by visible openings in their walls, so that the
protoplasm is continuous from cell to cell.
317. The cells contain chloroplasts, but their green
color is masked by the presence of a red or purple
coloring matter (phycoerythrin) and sometimes a blue
coloring matter (phj^cocyanin), so that the plants appear
red or purple, instead of green, although in fact they
are green; but lit must not be overlooked that a few
species are parasitic, and therefore devoid of coloring
matter!
318. The Red Algae are propagated by non-ciliated,
naked cells which are separated from the plant, either
205
206 PHYLUM VI. RHODOPHYCEAE
singly C'monospores") or in groups of fours ('Hetra-
spores"); these float away and on germination give rise
to new plants. They are generated heterogamically by
the union of non-motile sperms with enclosed eggs,
usually resulting in the growth of branching, sporebearing
filaments, mostly covered, and constituting a primitive
many-spored fruit (^'cystocarp").
319. In those species (by far the greater number of the
Red Seaweeds) in which tetraspores are produced, these
give rise to the sexual plants which
are mostly dioecious. The carpospores
from the latter give rise, in their turn,
to the tetrasporic plants. The nuclei
of the latter possess the diploid number
FiQ. 90. — Tetraspores. p ^ ±^ r j.i j*
of chromosomes; those oi the former
the haploid number, the reduction of chromosomes tak-
ing place during the divisions leading to the production
of the tetraspores.
320. Here the dominant characters are the reddish
pigment added to the chlorophyll of the cells, and the
development of the zygote into a sporiferous, usually
covered, tissue (the spore fruit; cystocarp). The im-
portant secondary characters are the definite and final
attainment of heterogamy, and the mostly symmetrically
branched and basally rooted plant body.
For the most part the Red Algae grow at very consider-
able depths in the waters of the ocean, although a few
occur near the shore, and a very few live in fresh water.
They are more abundant in the warmer waters, and be-
come less frequent as we go toward the poles. The
number of known species is about three thousand.
321. This phylum as a whole is poorly understood.
Very little consideration has been given to the physical
modification these plants have suffered through living
RED SEAWEEDS 207
(1) at such depths (where the Ught is greatly modified),
and also (2) in waters of such considerable salinity. It
is probal^le that this modification has masked their true
relationship to other plants, as well as to one another.
322. One of the lowest of the Red Algae is the common
"Laver" (PorphjTa), of the class bangioideap:, of all
coasts, in which the erect, deep purple, leaf-like, and
basally rooted, plant body is composed of a single layer
of cells. They propagate by monospores borne in the
cell layer. In their very simple generation certain cells
of the cell layer divide into non-ciliated sperms, while
others ])ecome very slightly modified into oogones, each
containing a single egg. The latter is fertilized by the
entrance of the sperm through an opening in the cell
wall, after which the zygote develops into usually eight
spores. The fruit is thus of very simple structure.
323. In Nemalion (which with the succeeding plants
belongs to the class florideae), a branching, filamentous
marine Red Alga, the clustered antherids
produce small spherical, non-ciliated
sperms. The oogone is prolonged into a
slender structure, the trichogyne, and to
this latter the sperm adheres and fertilizes
the egg. After fertilization the egg divides,
and each new cell sends out short crowded
branches which bear terminal spores. Here no protec-
tive envelope covers the spores, the fruit being very
simple. Asexual reproduction is not known.
324. Here may ])e noted briefly the Corallines (('oral-
lina) which are filamentous Red Algae which become so
heavily coated with lime as to efYectually hide their cells.
This lime coating is like an ancient coat of mail with its
flexible joints at intervals. The antherids and oogones
are in separate terminal cup-shaped structures, those con-
208 PHYLUM VI. RHODOPHYCEAE
taining the oogones becoming the fruit after fertilization.
Tetraspores occur in similar cup-shaped structures.
325. Polysiphonia contains plants in Avhich the branch-
ing, filamentous plant body is composed of more than one
row of cells, usually of a central row surrounded by an
outer layer, completely covering it. These shallow-
water plants are often of marked beauty both in struc-
ture and coloring. The tetraspores are
produced in unmodified or slightly swollen
branches, and originate within the tissues,
but with the increase in size of the tetra-
sporangia they eventually reach the surface
and sUp out as large, deeply colored naked
Polysiphonia. ccUs. The spccial antheridial branches
consist of a central axis with numerous
short, crowded, radiating branchlets whose extremi-
ties (antherids) abstrict the naked, colorless sperms.
The oogone possesses a trichogyne, and is surrounded by
a few protective cells. The sperms carried by currents
of water come in contact with the trichogyne, and
attach themselves to it and form cell walls. The nucleus
of one passes into the trichogyne, and unites with that of
the oogone. The oogone now fuses (for nutritive pur-
poses, as there are no nuclear fusions) with a large nearby
cell (the auxiliary cell) into which the zygote nucleus
passes, and from which arise the filaments which produce
the carpospores. In the meantime the surrounding
cells produce an urn-shaped structure (pericarp) w^th
an opening at the top from which the liaked carpospores
escape at maturity.
326, Irish Moss (Chondrus) is so easily obtained at the
apothecaries that it may well be cited as one with a
parenchymatous, much branched plant body. The
oogones and afterward the spore fruits are immersed in
RED SEAWEEDS 209
the substance of the plant body. The plants are col-
lected, washed and dried and so preserved for human food
(blanc mange) and especially as a food
for convalescents. The structure of Cal-
lymenia is similar to that of Chondrus.
327. Among the very commonly col-
lected Red Algae on either coast are speci-
mens of Plocamium remarkable for the
beauty of its color and the regularity of
its branching.
Laboratory Studies, (a) It is better for the student to
stud}^ the li\'ing plants of this phjdum at the seashore, but the
beginner should not fail to make a study of such specimens as
may be accessible. Specimens for the study of structure should
be preserved in alcohol or formalin, using sea-water instead of
fresh water. However, much may be made out by the careful
examination of dried specimens which may be obtained from
dealers. Red Seaweeds may often be obtained ''in the rough'*
which can be moistened and then pressed out and dried for
study. Such material will often yield quite good si)ecimens.
Good mounted microscopic specimens may sometimes be ob-
tained showing the structure of the plant as well as of the sexual
and asexual reproductive organs.
(b) Make careful microscopical examination of Poly-
si})honia using alcoholic or formalin material. Such mounts
should be made in sea-water or a 3 per cent, salt solution to
avoid the swelling of the cell walls. In the course of the study
the following should be noted: (i) the cellular structure of the
plant body, (ii) the tetraspores, (iii) the antherids, (iv) the
oogones (difficult to find), (v) the cystocarps with their sj^orcs
(carposporos). The closely related Dasya may be substituted
for Polysii)honia.
(c) Study the tissue of Chondrus.
(d) Dried specimens of some or all of the following genera,
mounted on heavy white paper, or cardboard, should be
available for macroscopic examination.
Porphvra, ]5atrachospermum, Corallina, Grinnellia, Xito-
phyllum, Polysiphonia, Dasya, Chondrus, Callophyllis, and
Plocamium.
u
210 PHIlTLUM VI. RHODOPHYCEAE
LITERATURE OF RHODOPHYCEAE
George Murray, An Introduction to the Study of Seaweeds,
London, 1895.
G. B. De Toxi, Sylloge Algarum, Vol. IV, Padua, 1897-1905.
W. G. Farlow, Marine Algae of New England and Adjacent
Coast, Washington, 1881.
CHAPTER XIII
PHYLUM VII. CARPOMYCETEAE
THE HIGHER FUNGI
328. The plants here brought together are all hystero-
phytes, being destitute of chlorophyll or any other simi-
lar coloring matter with physiological significance. In
accordance with the theory underlying the treatment of
all plant phyla in this book these hysterophytes must
have been derived from some of the preceding holophytes,
and it seems most probable that they came from the plants
in the phylum immediately preceding this one. In other
words, it is here assumed that the Higher Fungi arc allied
in structure to the Red Algae, and that the striking differ-
ences between them are correlated principally with the
change from the holophytic to the hysterophytic habit,
but it must be remembered also that the Red Algae arc
aquatic plants, while nearly all the Higher Fungi have
adapted themselves to terrestrial or aerial (non-aquatic)
conditions.
329. The Higher Fungi may be characterized as fol-
lows: They are filamentous plants, whose cells are always
without chlorophyll. Visible protoplasmic connections
between cell and cell are common. The filaments are
mostly isolated, but sometimes they are compacted into
parenchymatous masses, yet in few cases is there a con-
spicuous plant body comparable to the body of the re-
lated chlorophyll-bearing plants. This obsolescence of
the plant body results from the abandonment of tlie holo-
phytic habit, which has rendered chlorophyll-bearing
211
212 PHYLUM VII. CARPOMYCETEAE
cells unnecessary. The vestiges of the plant body are
present mainly as root-like absorbing organs, which di-
rectly bear the reproductive structures.
330. The Higher Fungi are propagated mainly by (1)
the separation of special terminal cells (conidia),and (2)
the separation of considerable fragments of the original
plant body. Zoospores are unknown in this phylum.
They generate by the union of the protoplasm of an an-
therid with the egg in an oogone, resulting in the produc-
tion of a spore-fruit (sporocarp) consisting of (1) sporog-
enous and (2) sterile tissues. In the fertilization of the
egg no instance is known of the production of motile
sperms.
331. Because of the reduction of the plant body the
spore-bearing structures, asexual and sexual, appear to
be relatively large. Moreover, because of the dependent
habit of the Higher Fungi it is necessary that many spores
should be produced, so that correlated with their depend-
ence is the great increase in the number of spores, and the
size of the spore-bearing structures. Thus it happens
that in many cases there is an actual increase in the size
and development of the spore-bearing structures, espe-
cially of the spore fruits. In many Higher Fungi no
sexual organs have been found, and it is thought that they
may have disappeared through the degradation of the
plant body.
332. This phylum contains about 64,000 known spe-
cies, and these may be arranged under three classes, with
an additional group of poorly understood, and unassorted
plants.
A. Spore fruits containing one or more asci, with ascospores.
Class ASCOSPOREAE.
B. Spore fruits containing one or more basidia, with basidio-
spores. Class Basidiosporeae.
ASCOSPHOREAE 213
C. Spore fruits much reduced, containing teliospores.
Class Teliosporeae.
D. Asci, basidia or teliospores unknown (artificial group).
Fungi Imperfecti.
Class 14. ASCOSPOREAE. The Ascus Fungi.
333. This large class includes chlorophyll-less plants
which differ much in size and appearance, but which agree
in producing their fruit-spores (carpo-
spores) in sacs (asci), and because they
are in sacs they are called sac-spores or
ascospores. These spore-bearing sacs
(singular, ascus; plural, asci) are end-
cells in the sporogenous tissue of the
fruit of the fungus, and they tend to Fio. 94.— Deveiop-
. . r 'f ^ • mcnt of asci and
develop m a layer of uniform height — ascospores.
the so-called ''h3^menium."
334. The sexual organs where known consist of oogones
and antherids, and, after fertilization, produce a spore-
fruit (sporocarp) which includes the sacs and sac-spores
(ascospores). The most common number of ascospores
is eight in each ascus; but it sometimes exceeds, and fre-
quently falls short, of this number, there being sometimes
no more than one or two.
335. In addition to the ascospores there are generally
one or more other kinds of spores which are developed
asexually. Some of these are doubtless to be regarded as
the equivalents of the conidia of the lower groups, and
accordingly will be so named here.
336. The Ascus Fungi include about 29,000 species,
representing 15 orders and 80 families. In the treat-
ment hero a selection has been made of representative
forms.
214 PHYLUM VII. CARPOMYCETEAE
The Disk "Lichens" (ORDER DISCOLICHENES)
337. The primitive Asciis Fungi (Ascosporeae) appear to
have been parasitic on small, green algae (myxophyceae
and khlorophyceae), and indeed this may have first
taken place in the water. It is known that some of the