326 THE DOCTRINE OF DESCENT. 



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 lilce final forms (see p. 2i). Nay, this 

 hypothesis does more, for " even 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." Kolliker's polyphyletic 

 hypothesis put an end to all difficulties, and, among others, it ex- 

 plains the so-called " representative forms " to be mentioned in our 

 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, KoUiker 

 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 

 opposite poles. Koliiker (p. 44) thus sums up his fundamental 

 view — " that in and with the first origin of organic matter and of 

 organisms, the whole plan of development, the collective series of 

 possibilities, were also potentially given, but that various external 

 impulses operated determinatively on individual developments, and 

 impressed a definite stamp upon them." Notwithstanding the 



