EVIDENCE FROM COLONIAL OR COMPOUND ANIMALS. 293 



egg, it gives origin by budding to other hydrse which break away from 

 the parent-organism, and live an independent existence. But as these 

 buds, although independent of the parent-body, nevertheless represent 

 part of the development of the single egg, we see that the " hydra- 

 individual " is not the parent-hydra alone, but that parent, plus all the 

 buds or hydrae which are produced by it. The next " individual" exist- 

 ence begins with the production of an egg. Till that event happens, 

 all the hydrae, produced by budding or otherwise, are merely parts of 

 an individual, and have of themselves no distinct personality. With 

 the zoophyte and the hydra, therefore, the case for the " individual 

 existence," as represented by the compound animal (i.e. by the single 

 animal plus its buds) seems clear. Quoting Professor Huxley once 

 more, we may say that " the multiplication of mouths and stomachs " 

 in a zoophyte (Fig. 197, 2) as the result of the budding of new 

 members of the colony " no more makes it an aggregation of different 

 individuals than the multiplication of segments and legs in a centipede 

 converts that arthropod into a compound animal." " The zoophyte," 

 continues the voice of authority, " is a differentiation of a whole into 

 many parts, and the use of any terminology which implies that it 

 results from the coalescence of many parts into a whole is to be 

 deprecated." The plant-lice (Fig. 197, 3) are to be viewed in pre- 

 cisely the same light. For, as Professor Huxley remarks, " no doubt 

 it sounds paradoxical to speak of a million of aphides, for example, 

 as parts of one morphological individual ; but beyond the momentary 

 shock of the paradox, no harm is done. On the other hand, if the 

 asexual (i.e. the products of the pseudova) aphides (Fig. 197, 3, ee) 

 are held to be individuals, it follows as a logical consequence, not 

 only that all the polypes on a cordylophora (or zoophyte) are ' feeding 



individuals,' while the stem must be a ' stump individual,' 



but that the eyes and legs of a lobster are * ocular ' and ' locomotive 

 individuals.' And this conception is not only somewhat more 

 paradoxical than the other, but suggests a conception of the origin 

 of the complexity of animal structure which is wholly inconsistent 

 with fact." 



The point to which our inquiries have led us may be summed up 

 in the conclusions, firstly, that animals exist either as simple or as 

 compound " individuals " the former typified by the higher animals at 

 large, and the latter by the zoophyte and the tapeworm tribe. A 

 second inference deducible from our study, is that the personality of an 

 animal is in reality the direct result, of its development, and of the 

 manner in which its parts and organs are structurally related to each 

 other. And a third deduction follows from our biological experience, 

 namely, that the separate parts or " zooids," as we term them of a 

 compound individual, are not necessarily connected by structural ties 

 to the parent or primitive form. On the contrary, like the detached 



