REFERENCES AND QUOTATIONS. 325 
of forms of the animate world” (p. 3). Except decided dualists, no 
one disputes the first part of Kélliker’s thesis. But the identifica- 
tion of the development of the organic individual, excluding the 
law of heredity, with the simple process of crystallization, or any 
other operation of chemical combination repeating itself under 
given conditions, scarcely needs a detailed refutation. Kélliker 
says, and tries to prove, that the so-called monophyletic hypo- 
thesis, according to which the different families of organisms are 
derived from a single primordial form, has to struggle with insur- 
mountable difficulties; that the hypothesis of descent from many 
families (polyphyletic) possesses more probability. If this be 
admitted, then—and here comes a bold leap of the imagination— 
the adherent of the polyphyletic hypothesis finds himself in a 
position to attribute different pedigrees and primordial forms not 
only to the higher divisions, but even to their genera, and to assume 
their independent origin. Nay, it even seems credible that the 
self-same species may appear in different pedigrees; as by the 
incontrovertible supposition of general laws of formation, it cannot 
be seen why like primary shapes should not, under certain circum- 
stances, be able to lead to like final forms (see p. 21). Nay, this 
hypothesis does more, for “ éven if individuals of the same species 
occupy remote localities, as, for instance, Pennatula phosphorea, 
Funiculina quadrangularis, Renilla reniformis, &c., it is surely more 
fitting to assume their independent origin.” Kélliker’s polyphyletic 
hypothesis put an end to all difficulties, and, among others, it ex- 
plains the so-called “representative forms” to be mentioned in cur 
‘tenth chapter; for, from “this standpoint, it is credible that these 
forms are not genetically connected, but belong to different pedi- 
grees” (p. 23). And all this, and much more, is supposed to be 
conceivable, because the world of organisms, in its consecutive 
development, follows intrinsic causes or definite laws of formation, 
“laws which, in a perfectly definite manner, urge on the organisms, 
to constantly higher development.” At the same time, Kolliker 
deliberates (p. 38) whether, just as here germs and buds, so also 
free existing youthful forms of animals did not possess the power 
of striking out a development different from the typical one, which 
freedom must be severely mulcted by the law of development, 
which can and must create individuals of the same species at the 
