EVIDENCE FROM COLONIAL OR COMPOUND ANIMALS. 277 



and defined individuality in that of the compound colony. For 

 occasionally particles or offshoots of the amoeba's protoplasmic body 

 detach themselves therefrom, and pass away like precocious emigrants 

 from the parent-frame to assume all the functions of amoebae on their 

 own account. In this way, and through the exercise of the simplest 

 reproductive process we know of namely, that of " fission," or simple 

 division of an animal's body into two or more new beings the 

 amoeba-body converts itself from a single " individual " into a mother- 

 colony, with offshoots and emigrants seeking a life and existence of 

 their own. And, last of all, in the gregarina itself, we may find 

 certain important variations in structure which seem to threaten the 

 destruction of the individualism of its body, and to merge the 

 individual in the crowd. For we know not merely of gregarinae 

 which consist apparently of but one mass of protoplasm, as already 

 described, but of others which 

 exhibit a division of body into 

 two (Fig. 183, d) or even three 

 compartments. What the signi- 

 ficance of this tendency to divi- 

 sion or segregation may be, is yet 

 matter of conjecture ; but at first 

 sight its meaning would seem to 

 foreshadow the same destruction 

 of individual constitution which, 

 in their development, these or- 

 ganisms unquestionably exhibit. 

 Even in the lowest animals, 

 each consisting of a minute mass 

 of protoplasm, there is thus ob- 

 served a tendency, at some period 

 or other of their life-history, to 

 depart from the single state, and 

 l)y division, or, as it is named, 

 " segregation," of their substance, 

 to form a "colonial" or com- 

 pound organisation. But even 

 in the lower confines of animal 

 life, which harbour the amoebae 

 .and gregarinae as typical tenants, 



are represented states and phases of organisation which are purely and 

 typically " colonial." Thus, that low form of life known as Myxo- 

 dictyum normally exists as a collection of protoplasmic particles, such 

 as would be exactly imitated if a number of arricebae banded and 

 fused themselves together. It is equally interesting to note that the 

 vast majority of the Foraminifera (Fig. 185), or " chalk- animalcules," 



FIG. 185. FORAMINIFERA. 



