ZTGNEMAOE^. 



233 



similar processes from parallel filaments {a, b. Fig. 156). 

 Upon meeting, the ends of the processes flatten upon each 

 other, the walls fuse together, and soon afterward become 

 absorbed, thus making a channel leading from one cell 

 to the other (Fig. 157). Through this channel the proto- 



Fia. 156. 



Pig 156 —Beginning of tlie process of conjugation m Spirogyra longata. o, 

 beginning of tlie formation of lateral tubes ; b, e, tlie tubes in contact. X 550. 



Tie 157 —Conjugation of Spirogyra longata. A, tlie protoplasm passing from 

 one cell to the oiher at a ; ft, the mass of protoplasm formed by the union of the 

 protoplasmic contents of the two cells. „ „ ™. ^ . ., 



£ two voun" zygospores (c), each with a cell-wall. They contain numerous oil 

 drops, and are still enclosed by the walls of the parent cell. X 550.— After Sachs. 



plasm of one cell passes into the other, and the two fuse into 

 one mass, which becomes rounded, and in a short time secretes 

 a wall of cellulose around itself (Fig. 157, A and B). The 

 zygospore thus formed is set free by the decay of the dead 



