CONJUGAT.E. 



107 



becoming liberated owing to the decay of the parent plant, 

 and sinks into the mud as a resting-spore. In some 

 instances tlie zygospore germinates 

 almost at once, and while yet en- 

 closed in the mother-cell. 



The fact of all the contracted 

 protoplasm masses passing from the 

 cells of one of the conjugating plants 

 and coalescing with the passive pro- 

 toplasm contained in the cells of the 

 second plant, certainly suggests an 

 indication of sexual differentiation, 

 the plant from which the proto- 

 plasm migrates being considered 

 the male, and the one in which the 

 protoplasm remains passive, the 

 female. The masses of contracted 

 protoplasm in the cells of the latter 

 are also slightly larger than in the 

 former, and other slight differences 

 also exist; but a true differentia- 

 tion of sex is not yet stereotyped, 

 as the following modifications of 

 the above process show. In some 

 cases so-called lateral conjugation 

 between two cells of the same fila- 

 ment takes place, processes from 

 two contiguous cells grow outwards, 



Fig. 19. — (x 4D0). Conjugation of the cells of two individuals of 5/;>-ogj//-(Z. 

 A, two cells prepared for conjugation ; at a the filaments have begun 

 to swell towards each other ; cl, spiral bands of protoplasm. K, nucleus. 

 At B the protoplasm of the cell f is fusing with that of the cell /'. Z is 

 a perfectly-formed zygospore which has secreted a cell-wall. (From 

 Prantl.) 



