124 THE PROTOZOA 



lata, on the other hand, the division of the body is usually longi- 

 tudinal. In any case, the two products of fission may be equal or 

 subequal in size, without perceptible difference of parent and 

 young ; or they may be markedly unequal, in which case parent 

 and offspring can be distinguished clearly. 



The various organs of the body may be doubled before division : 

 either by splitting or new growth of one set ; or, if there are many 

 organs of a particular kind present, such as the cilia and tricho- 

 cysts of Ciliata, they may be simply shared between the two 

 daughter-organisms ; or, finally, any given organ present in the 

 animal before division may be retained by one of the two daughter- 

 individuals, while the other forms the organ in question anew after 

 division. Thus, in Ciliata one daughter-individual retains the old 

 peristome ; the other forms a new one for itself. The greater the 

 number of organs formed afresh in the daughter-individual, the 

 more advanced is the transition from ordinary fission towards 

 budding. 



In typical gemmation small portions of the parent-organism 

 grow out, into which pass either nuclei, the products of the division 

 of the parent-nucleus (Fig. 68), or of budding from the nucleus of 

 the parent (Fig. 55), or chromidia, alone or together with a nucleus. 

 Such buds may arise on the surface of the parent-body, or they 

 may be cut off in the interior of the cytoplasm of the parent, and 

 may remain for some time within its body. Endogenous budding 

 of this kind is seen in the Neosporidia (p. 325), in the Acinetaria, 

 where it is combined with nuclear budding, and in Arcella (Fig. 80) 

 and some amoebae, where it is combined with formation of secondary 

 nuclei from chromidia. 



Bibliography. For references see p. 479. 



