Prof. Owen’s Address before the British Association. 425 
ganization. What has been effected and recommended, i n regard to 
homologous parts in the Vertebrata, should be followed out in the Ar- 
ticulata and ee In re rd t to the constituents of the crust or 
kingdom. e of homology in reget to the praees 
has sufficed ee demonstrat od the segment of the crust is not a hollow 
xpanded homologue e segment of the —s aaa of a vertebrate. 
that whieh is essential to the exactitude of his science—a nomenclature 
a to express his conviction of the different sdlationl of similitude. 
difficult and recondite are the questions in face of which the march 
of Homology is now irresistibly — the philosophic observer. 
Such, for instance, as the following: Are the nervous, muscular, iges- 
tive, circulating and generative systems of in more than functionally 
similar in any two primary provinces of the animal kingdom? Are 
the homologies of entire systems to be judged of by their functional 
and structural connexions, rather than by the plan and course of their 
formation in the embryo? It may be doubted if embryology alone is 
en of the question whether homology can be predicated of the 
. : ata 
ca 
It is seducant, ss of the lower — of embryological c 
to note that the great leading divisions of the animal kingdom, based by 
Cuiver on Comparative Anatomy, have merely been confirmed by von 
— later developmental researches. 
Parthenogenesis—John Hunter first cnet the g 
every art of a vegetable is ‘a whole, so ae. it is oe of being 
multiplied as far as it can be divided -into distinct parts ; the other, that 
certain of those parts become reproductive organs, and produce fertile 
seeds.” Hunter also remarked, that “ the first principle operated in many 
animals which propagate their species by buds ir ;” but that, 
operated in vege 
of Trembley on the fresh water ss 5 ose of 
a those cons Bonnet on _ Aphides, had ma to li iit the staneueides 
inne formal 
*s m, “omne vivem ab ove,” appears to be 
si we yas seagte above quoted. The er 
i, eg hi and others had contract 
7 » could with any lusty b be 
: oo Vor. XXVI, No. 78.—NOV., 1855. 
55 
¢ 
