EVIDENCE FROM COLONIAL OR COMPOUND ANIMALS. 291 



colony (Fig. 197, 2), with its budded branches (<?) and its ever- 

 increasing wealth of members. For plant-lice reproduction is in 

 reality a process of budding, and the colonial constitution of the 

 insects is really veiled and masked by their freedom from the parent- 

 stock. They may, in truth, be compared to those free-swimming 

 " jelly-fish " buds which the zoophyte develops upon and liberates 

 from its branches, but which remain, nevertheless, in the gaze of 

 philosophy, essential parts and constituent units of the animal-tree 

 which gave them birth. Lastly, let us bear in mind that the egg itself 

 is merely a reproductive bud; and that there are gradations thus to be 

 witnessed leading from the true egg, with its normal development, 

 after fertilisation, to the pseud-ovum with its bud-like career, and 

 finally to the bud itself, which, as we shall see, never attains, let its 

 development be what it may, to the rank of a true individual animal. 

 A glance at Fig. 197 will serve to show the correspondence between 

 the development of aphides (3), zoophyte (2), and plant (i). In each 

 case, the bulk of the compound organism is- provided for by a process 

 of "budding;" whilst, as the colony reaches its higher development, 

 the production of new and independent individuals, through eggs and 

 seeds (//, i) respectively, is witnessed. 



Rassemblons des faits pour nous donner des idees taking the 

 term "ideas" as synonymous with that philosophy the praises of 

 which have already been sufficiently extolled. From the array of 

 facts through which we have progressed, what ideas or interences 

 concerning the origin of animal colonies can be reasonably derived ? 

 And, firstly, let us inquire what definition biology is prepared to offer 

 as the criterion of animal or plant individuality. It is perfectly clear 

 that some such test of an animal's nature is demanded, for instance, 

 by the very diversity of form and constitution which the animal 

 kingdom presents. An " individual " animal we may readily define, in 

 respect of its structural constitution, as one in which all its parts and 

 organs exist. in such intimate relationship, that interference with one 

 organ or series means the disorganisation of all. Close and inti- 

 mately connected structure, forms in reality the plainest criterion of 

 the " individual " animal viewed from that side of biology which 

 regards morphology or " structure " as the basis of its philosophy. 

 The integral constitution of its material parts is thus the plain test 

 of an animal's " individuality," from the structural point of view. On 

 such grounds, the man or the dog is obviously a much more typical 

 " individual " than a " newt," which can part with its tail or legs, and 

 yet live and develop new members in the place of the injured parts ; 

 and the newt, in turn, is a truer " individual," judged by its structural 

 interdependence, than the zoophyte, whose buds as they fall are 

 replaced without material disorganisation of its constitution. 

 Professor Asa Gray well sums up the structural view of the 



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