less troublesome in their eating. But when we lose the seeds
entirely of a whole group of related plant kinds we may find our-
selves, as we have found ourselves actually in many cases, at the
end of our powers of amelioration of these plant sorts. Burbank
believes that the very fact that plants when grown asexually always
sooner or later lose their power to produce seeds is almost suffi-
cient proof (if such proof is needed) that acquired characters are
"Another of Burbank's open secrets of success is the great range
of his experimentation nothing is too bold for him to attempt.
the chances of failure are never too great to frighten him. And
another secret is the great extent, as regards material used, of each
experiment. His beds of seedlings contain hundreds, often thou-
sands, of individuals where other men are content with hundreds.
Another element in his work is his prodigality of time. Experi-
ments begun twenty years ago are actually still under way.
"In all that I have so far written, I have purposely kept to gen-
eral statements applicable to Burbank's work as a whole. My
readers might be more interested, perhaps, to have some illustra-
tions of the application of various processes of making new sorts
of things, some analytical account of the history of various specific
'new creations.' but considerations of space practically forbid this.
Just a few briefly described examples must suffice. More than is
generally imagined, perhaps, Burbank uses pure selection to get
new things. From the famous golden orange coloured California
poppy (Escholtsia) he has produced a fixed new crimson form by
OTHER THEORIES OF SPECIES-FORMING. 315
selection alone. That is, noticing, somewhere, sometime, an Esclwlt-
sia individual varying slightly redder, he promptly took posses-
sion of it, raised young poppies from its seeds, selected from among
them those varying in a similar direction, raised new generations
from them and so on until now he who wishes may have his
California poppies of a strange glowing crimson for the price of a
little package of seed, where formerly he was perforce content
with the golden orange. For me the golden orange suffices, but
that 'does not detract from my eager interest in the flower-painting
methods of Mr. Burbank. Even more striking a result is his blue
Shirley poppy, produced also solely by repeated selection from
the crimson field poppy of Europe. 'We have long had various
shades of black and crimson and white poppies, but no shade of
blue. Out of 200,000 seedlings I found one showing a faintest trace
of sky blue and planted the seed from it, and got next year one
pretty blue one out of many thousand, and now I have one almost
"But another brilliant new poppy was made in a different way.
The pollen of Papaver pilosum, a butter-coloured poppy, was put
on the pistils of the Bride, a common pure white variety of
Papaver somniferunt (double), and in the progeny of this cross was
got a fire-coloured single form. The character of singleness was
common to the ancestors of both parents, the character of fire colour
in the lineage of somnifcrum only, although the red of the new
form is brighter than ever before known in the somnifera series.
Both characteristics were absent (or rather latent) in both parents.
And yet the perturbing influence of the hybridisation brought to
the fore again these ancestral characters. The foliage of this fire
poppy is intermediate in type between that of the two parents.
"The history of the stoneless and seedless plum, now being
slowly developed by Burbanks, shows an interesting combination of
selection, hybridisation, and reselecting. Mr. Burbank found a
plum in a small wild plum species with only a part of a stone.
He crossed this wild species with the French prune; in the first
generation he got most individuals with whole stones, some with
parts of a stone, and even some with no stone. Through three
generations he has now carried his line by steadily selecting, and
the percentage of no-stone fruits is slowly increasing, while quality,
beauty, and productiveness are also increasing at the same time.
"The plum-cot is the result of crossing the Japanese plum and the
apricot. The plum-cot, however, has not yet become a fixed variety
and may never be, as it tends to revert to the plum and apricot
about equally, although with also a tendency to remain fixed, which
tendency may be made permanent.
316 DARWINISM TO-DAY.
"Most of Burbank's plums and prunes are the result of multiple
crossings in which the Japanese plums have played an important
part. Hundreds of thousands of seedlings have been grown and
carefully worked over in the twenty years of experimenting with
plums, and single trees have been made to carry as many as 600
varying seedling grafts. The Bartlett plum, cross of the bitter
Chinese Simoni and the Delaware, itself a Simoni hybrid, has the
exact fragrance and flavour of the Bartlett pear. The Climax, a
successful shipping plum, is also a cross of the Simoni and the
Japanese triflora. This Chinese Simoni produces almost no pollen,
but few grains of it ever having been obtained. But these few
grains have enabled Burbank to revolutionise the whole plum
shipping industry. The sugar prune, which promises to supplant
the French prune in California, is a selected product of a second or
third generation variety of the Petite d'Agen, a somewhat variable
"Next in extent probably to Burbank's work with plums and
prunes is his long and successful experimentation with berries.
This has extended through twenty-five years of constant attention,
has involved the use, in hybridisations, of forty different species of
Rubus, and has resulted in the origination of a score of new com-
mercial varieties, mostly obtained through various hybridisations of
dewberries, blackberries, and raspberries. Among these may spe-
cially be mentioned the Primus, a hybrid of the western dewberry
(R. ursinus) and the Siberian raspberry (R. crat&gifolius'), fixed
in the first generation, which ripens its main crop before most of
the standard varieties of raspberries and blackberries commence to
bloom. In this Primus berry, we have the exceptional instance of
a strong variation, due to hybridisation, breeding true from the
time of its first appearance. It usually takes about six generations
to fix a new variety, but like de Vries's evening primrose mutations,
the Primus berry is a fixed new form from the time of its beginning.
An interesting feature of Mr. Burbank's brief account, in his 'New
Creations' catalogue of 1894, of the berry experimentation, is a re-
production of a photograph showing 'a sample pile of brush, 12
ft. wide, 14 ft. high, and 22 ft. long, containing 65,000 two- and
three-year-old seedling berry bushes (40,000 blackberry y rasp-
berry hybrids and 25,000 Shaffer y Gregg hybrids) all dug up
with their crop of ripening berries. The photograph is introduced
to give the reader some idea of the work necessary to produce a
satisfactory new race of berries. 'Of the 40,000 blackberry y rasp-
berry hybrids of this kind, "Phenomenal" is the only one now in
existence. From the other 25,000 hybrids, two dozen bushes were
reserved for further trial.'
OTHER THEORIES OF SPECIES-FORMING. 317
"An astonishing result of the hybridisation between the black
walnut, Juglans nigra, used as the pistillate parent, and the Cali-
fornia walnut, /. californica, staminate parent, are walnut trees
which grow with such an amazing vigour and rapidity that they
increase in size at least twice as fast as the combined growth of
both parents. Many tremendous growers are got in the first gen-
eration, but in the second there are included some of the most
rapidly growing trees, perhaps, in the world. This hybrid has
clean-cut, glossy bright-green leaves from two to three feet long
with a sweet odour like that of apples, but it produces few nuts.
Curiously enough the result of hybridisation by using the pollen
of nigra on pistils of californica produces in abundance large nuts
of a quality superior to that possessed by either parent.
"The famous Shasta daisy is the result of a multiple crossing
between an American and a European species of field daisy and
then between these hybrids and a Japanese form. The fragrant
calla, known as 'Fragrance,' is descended from a single individual
found by Burbank while critically examining a block of Little Gem
calla seedlings. He was surprised in this examination by a fra-
grance resembing that of violets or water-lilies ; as he had long
been seeking a fragrant calla, the individual giving this perfume was
carefully hunted out. No farther selecting was done; this plant
was the single ancestor of the fragrant new race.
"And so one might go on for pages, but with slight variations in
detail all these pages would tell only the same story : the stimulating
or inducing of variability by environmental influences and by hybrid-
isations ; the search after, and keen recognition of promising spe-
cial variations ; the selection of the plants showing these variations ;
rearing new generations from them, repeated selection, and new
hybridisations to eliminate this characteristic or introduce that,
and on until a desirable combination is found. Then the careful
fixing of this form or type by repeated selection through several
"But an end must be made of this. Let us, in a paragraph, simply
sum up the essential things in the scientific aspects of Burbank's
work. No new revelations to science of an overturning character;
but the revelation of the possibilities of accomplishment, based on
general principles already known, by an unusual man. No new laws
of evolution, but new facts, new data, new canons for special cases.
No new principle or process to substitute for selection, but a new
proof of the possibilities of the effectiveness of the old principle.
No new categories of variations, but an illuminating demonstration
of the possibilities of stimulating variability and of the reality of
this general variability as the fundamental transforming factor.
3 i8 DARWINISM TO-DAY.
No new evidence either to help the Darwinian factors to their death-
bed, or to strengthen their lease on life; for the 'man' factor in all
the selecting phenomena in Burbank's gardens excludes all 'natural'
factors. Here are some of Burbank's own words, touching these
matters that scientific men are particularly interested in, in his work :
" 'All scientists have found that preconceived notions, dogmas,
and all personal prejudice must be set aside, listening patiently,
quietly, and reverently to the lessons one by one which mother
nature has to teach, shedding light on that which before was a
mystery, so that all who will may see and know.
" 'Crossing gives the raiser of new plants the only means of
uniting the best qualities of each, but just as often the worst quali-
ties of each are combined and transmitted, so that to be of any
value it must be followed by rigid and persistent selection, and in
crossing, as in budding and grafting, the affinities can only be
demonstrated by actual test.
" 'All wild plants of any species are under almost identical envi-
ronments, having their energies taxed to the utmost in the fierce
struggle for existence. Any great variation under such circum-
stances is not likely to occur, and is much more likely to be stamped
out at once by its struggling competitors, unless the variation should
be of special use in competition, in which case it will survive, and
all others may be supplanted by it. Thus we see how new species.
are often produced by nature, but this is not her only mode. Crosses
and hybrids are very often found growing wild where two some-
what similar species grow contiguous, and if the combination hap-
pens to be a useful one, as it often does, the new creation is
encouraged by nature ; then time and environment fix it, and man
comes on the scene, perhaps ages later, and discovers it, and, not
knowing all the facts, wonders where the connecting links have
gone. It is botanically classified as a new species, which it is most
" 'In cultivated plants the life struggle is removed, and here we
find variation almost the rule rather than the exception.
" 'Varieties are the product of fixed laws, never of chance, and
with a knowledge of these laws we can improve the products of
nature, by employing nature's forces, in ameliorating old and produc-
ing new species and varieties better adapted to our necessities and
tastes. Better food, more sunshine, less arduous competition, will
of themselves induce variation in individual plants which will be
more or less transmitted to their seedlings, which, selected con-
secutively through a certain number of generations, will become
permanent. Environment here exerts an influence as in all chemical
cosmical, and celestial movements. These small increments from
OTHER THEORIES OF SPECIES-FORMING. 319-
environmental forces may produce a gradual or sudden change
according to circumstances. The combustion of food liberates the
moving force, environment guides it as it does the planets.
" 'When once the persistent type is broken up, old latent forces
may be liberated and types buried in the dim past reappear. This,
called atavism, is a concentration of ancestral forces reverberating-
echoes from varieties long since passed away, exhibiting them-
selves when from some cause, for instance crossing, present forces
are in a state of antagonism, division, perturbation, or weakness.
These echoes, if collected by crossing and selection, produce com-
binations of superlative importance and value.' "
7 Plate, L., "Uber die Bedeutung," etc., p. 220.
8 See Koken, Ernst, "Palaeontologie und Descendenzlehre," 1902.
Koken (Professor of Geology and Palaeontology in the University
Orthogenetic * Tubingen) is very explicit in the statements of his
variation in belief that the palaeontological records prove the exist-
palzontology. ence of orthogenetic variation and hence evolution.
"Das Darwin'sche Prinzip der Selektion ist nicht das einzige, das.
in Betracht kommt und es scheint nicht das wichtigste zu sein.
Vielfach vermissen wir in der palseontologischen Geschichte den
Hinweis auf ein Eingreifen des Kampfes urns Dasein und anderer-
seits heben sich Richtungen der Entwickelung heraus. welche nicht
in Beziehung zu einem Nutzen stehen, in einigen Fallen zu einer
Schadigung der socialen Bedingungen fiihren."
' For an account of the facts of one such case, see Kellogg, "Is
There Determinate Variation," Science, N. S., Vol. XXIV, pp. 621-
628, 1906. In this paper the gradual but obvious change from.
A case of ap- one dominant type of colour-pattern to another in
parent determi- the leaf-eating beetle Diabrotira soror (on the campus,
nate variation. o f Stanford University, California) during the last
ten years, is shown by statistical variation studies. It is shown
that such change is not explicable on a basis of intra-specific
selection, nor can it be interpreted as a direct ontogenic reaction
in each succeeding generation to changing climatic conditions. The
case is believed to be an example of definitive orthogenetic
Certain examples of presumable determinate variation have been;
recorded by Henslow ("The Origin of Species," Natural Science,.
p. 259, 1894). "In 1847, Prof. J. Buckman sowed seed of wild
parsnip in the garden of the Agricultural College, at Cirencester.
The seedlings began to vary, but in the same way, though in differ-
ent degrees. By selecting seed from the best rooted plants, the
acquired 'somatic' characters of an enlarged root, glabrous leaves,
etc., became fixed and hereditary; and 'The Student,' as he called*
it, having been 'improved' by Messrs. Sutton & Sons, is still
regarded as 'the best in the trade.' This is definite variation, ac-
cording to Darwin's definition, for those weeded out did not differ
from the selected, morphologically, except in degree, the variations
towards improvement not being quite fast enough to entitle them
"M. Carriere raised the radish of cultivation, Raphanus sativus,
L., from the wild species R. raphanistum, L., and moreover found
that the turnip-rooted form resulted from growing it in a heavy
soil, and the long-rooted one in a light soil.* Pliny records the
same fact as practised in Greece in his day, saying that the 'male'
(turnip form) could be produced from the 'female' (long form), by
growing it in 'a cloggy soil.' Both forms are now, of course,
hereditary by seed."
10 Nageli, C. von, "Mechanisch-physiologische Theorie der Ab-
11 Korschinsky, S., "Heterogenesis und Evolution," Naturwiss.
Wochcnschrift, Vol. XIV, pp. 273-278, 1899.
11 Recently, Georg Pfeffer ("Die Entwicklung," 1895) has pro-
posed a theory of orthogenetic evolution not very different from
the much earlier Nagelian one. Pfeffer postulates as
i nnerent ' n living matter a capacity for change and
for self-directing this change. The principle of
change or progress he calls the conception of "developrtiental-screw"
(Entwicklungsschraube) , and for directing this progress the con-
ception of "self-steering" (Selbststeuerung). Both these capacities
of individualised living stuff are something over and beyond the
mechanical and physico-chemical attributes of living matter. "On
the contrary," says Pfeffer, "life consists of the capacity (more
exactly the exercise of this capacity) of consciously permitting and
consciously influencing (that is, actually producing) through
physico-chemical phenomena changes in the matter or form of the
From this curious, though keen, critical, and constructive essay,
I quote as follows :
"Der Begriff der Entwickelungsschraube deckt sich eigentlich
vollig mit dem Begriff der Selbststeuerung der lebendigen Natur;
ich halte aber mit gutem Grunde beide Ausdriicke aufrecht, well
sie einer verschiedenen Betrachtung entspringen, namlich die
Selbststeuerung der mechanischen, die Entwickelungsschraube der
historischen, entwickelungsgeschichtlichen Betrachtungsweise ; die
Selbststeuerung ist das Prinzip der Herstellung des Gleichgewichtes
* This has been corroborated by M. Languet with the carrot. Soc.
Roy. et Cent. d'Agricult., 2d sen, Vol. II, 1846-7, p. 539.
OTHER THEORIES OF SPECIES-FORMING. 321
eines aus lebendigen Einheiten gebildeten Ganzen ; die Entwickel-
ungsschraube das Prinzip der veranderten Weiterfiihrung dieser
Gleichgewichtsverhaltnisse in der Zeit. Also ist, ebenso wie die
Selbststeuerung, auch die Entwickelungsschraube selbstthatig (pp.
12 and 13).
"Es ist hier nicht der Ort, die physikalischen wie die Unzahl der
chemischen Eigenschaften der lebendigen Grundsubstanz zu eror-
tern ; sie liegen freilich nicht auf der Hand, sind" aber im Ganzen
ziemlith leicht herzuleiten als das alien lebendigen protoplasmati-
schen Substanzen Gemeinsame. Es 'fallt aber Niemandem ein, bez.
sollte Niemandem einfallen, die physikalischen und chemischen
Eigenschaften der lebendigen Substanz als Lebens-Eigenschaften zu
betrachten; vielmehr besteht das Leben in der Fahigkeit (bez. der
Ausiibung der Fahigkeit), die durch chemisch-physikalische
Vorgange an dem Stoff oder der Form-Auspragung der Grund-
substanz bewirkten Veranderungen bewusst zu erleiden und bewusst
zu beeinflussen (bez. hervor zu bringen). Es hat also jeder kor-
perliche Vorgang der lebendigen Substanz seinen von ihm untrenn-
baren Bewusstseinsvorgang ; oder anders ausgedruckt: jeder Vor-
gang an lebendigen Wesen hat einen in chemisch-physikalische und
einen anderen in Bewusstseins-Verhaltnisse zerlegbaren Anteil.
Beide sind. Gegenstande wissenscfoaftlicher Betrachtung, dagegen
entzieht sich die Art und Weise des Zusammenhanges zwischen
beiden unserm Anschauungsvermogen, liegt also ausserhalb der
naturwissenschaftlichen Betrachtung und ist damit als gegeben
hinzunehmen" (p. 17).
A recent proposal of an orthogenetic theory of the general
character of Nageli's is that set out in O. F. Cook's "Aspects of
Kinetic Evolution," Proc. Wash. Acad. Sci., Vol. VIII, pp. 197-403,
13 Eimer, Th., "Die Entstehung der Arten auf Grund von Verer-
bung erworbener Eigenschaften nach den Gesetzen organischen
Wachsens," I, 1888 ; trans, into English, as "Organic
ofoS'enesTs! 7 Evolution," 1889; "Artbildung und Verwandschaft
bei den Schmetterlingen," I, 1889, II, 1895; "Ortho-
genesis bei Schmetterlinge" (Part II of "Die Entstehung der
Arten"), 1898; "Orthogenesis," 3 Internat. Congress Zool., 1895;
trans, in English as "On Orthogenesis and the Impotence of Natural
Selection in Species-Formation," 1898. This address, and Eimer's
other writings as well, are sadly marred by intemperate polemic
and the indulgence of personal rancor. He deems himself and his
views unfairly overlooked by biologists and seems to hold Weismann
personally responsible for this. Apart from these unfortunate
digressions his papers are extremely suggestive and logically and
322 DARWINISM TO-DAY.
keenly composed. I believe that Elmer's work and theories should
have more attention from students of evolution then they now get.
14 Dean, Bashford. "Evolution in a Determinate Line, as Illus-
trated by the Egg-Cases of Chimaeroid Fishes," Biol. Bull, Vol.
Apparent deter- VII, pp. 105-112, 10x14. In this paper the author
minate evolution, expresses his belief that the conditions existing in the
curious inter-related adaptations between eggs and egg-cases of the
shark-like fish, Chimsera, can be explained only on the basis of
determinate or orthogenetic modifications, in which modifications
neither natural selection nor the Lamarckian factors of use and
disuse can have played any part. The capsule or egg-case, although
"only indirectly connected with the egg, i.e., as a secretion formed
by the parent after the mechanism of heredity has already been
established in the egg, nevertheless foresees with startling exact-
ness the size and shape of the young fish when many months hence
it comes to hatch out, and it provides a series of progressive multi-
plications adapted to the physical needs of the young. It is evident,
accordingly, that if natural selection be adduced to explain the
present phenomena it encounters difficulties more numerous and
complex than in usual instances. In the latter cases selection con-
cerns itself with variations which affect the progeny directly; but
in the present case variations njust have occurred in the lines both
of the progeny and, indirectly, of its far less indifferent capsule-
forming capabilities with result that a succession of closely corre-
lated stages in variation must have coincided in both distinct con-
16 Plate, L., "Uber die Bedeutung," etc., p. 190 ff.
ie Rosa, Daniel, "La Riduzione Progressiva della Variabilita i
suoi Rapporti coll' Estinzione e coll' Origine della Specie," 1899.
Author believes that in animal life there is a gradual progressive
reduction of variation (or modification) necessitated by the well-
known fact that highly specialised forms have distinctly fewer lines
of modification, i. e. specialisation, left open to them than general-
ised forms; and that all groups of animals are of the nature of
series of more and more specialised forms. He bases this belief, as
far as facts go, on the well-known cases of the dying out of spe-
cialised species (Irish stag) and specialised groups (Cretaceous
reptiles), and on the alleged facts (which the author devotes many
pages to trying to show) that all present-day principal groups of
animals are related to each other solely by derivation from com-
mon very old and generalised ancestors. If there is less modifica-
tion possible, then there occurs actually less and less variability, and
the actually occurring variations will be only along certain lines,
i. e. there will be in this limited variability an actual basis for ortho-
OTHER THEORIES OF SPECIES-FORMING. 323
genesis. On the double basis of progressively less variation and of
the thus produced orthogenesis the author sees a factor in phylogeny
(organic evolution) which works, to some degree, independently of
natural selection or of Lamarckian factors. Rosa thinks he has
thus contributed to biology one of the always sought-for "unknown
factors in evolution."
17 In an interesting paper by Snodgrass, "The Relation of the Food
to the Size and Shape of the Bill in the Galapagos Genus Geospisa,"
Snodgrass's Auk, Vol. XIX, pp. 367-381, 1902, detailing the ex-