212 



BIOLOGY OF THE PROTOZOA 



Reorganization is indicated to some extent by these cases in which 

 the old flagellum is absorbed. It is still better indicated by a number 

 of flagellates in which the cytoplasmic kinetic elements, as well as 

 the flagella, are all absorbed and replaced by new combinations in 

 each of the daughter cells. Thus in Spongomonas splendida, accord- 

 ing to Hartmann and Chagas (1910) the old blepharoplasts and the 

 two flagella are absorbed and new ones are derived from centrioles 

 of the nuclear division figure (Fig. 49, p. 95). The phenomenon 

 cannot be regarded as typical of the simple flagellates, for in the 

 great majority the kinetic elements are self-perpetuating, even the 

 axostyles according to Kofoid and Swezy (1915) dividing in Tricho- 

 monas (Fig. 77, p. 145). This, however, has not been supported 

 by later workers. 



Fig. 106. 



-Vahlkampfia Umax. Nucleus in upper cell in full mitosis (promitosis). 

 (From Calkins.) 



An extreme case of reorganization is apparent in the two species 

 of Lophomonas (L. blattae and L. striata) first described by Janicki 

 (1915). Here the parental calyx, basal bodies, blepharoplasts and 

 rhizoplasts all degenerate during division (Fig. 105). At division a 

 cytoplasmic centriole first divides with a connecting fibril which is 

 retained throughout as a parademose. The nucleus emerges from 

 the calyx in which it normally lies, and moves with the spindle to 

 the posterior end of the cell. The spindle takes a position at right 

 angles to the long axis of the cell; chromosomes, probably eight in 

 number, are formed and divided, and two daughter nuclei result, 

 each of which is enclosed by a new calyx while new basal bodies and 

 blepharoplasts apparently arise from the polar centrioles (Fig. 

 105). Thus the old kinetic complex, with the exception of the 

 cytoplasmic centriole, is discarded and entirely new_aggregates are 

 formed. 



