FERTILIZATION AND FUUIT-FORMATION IN CRYPTOGAMS. 



53 



the water. The actual fact is that spermatozoids which come into the vicinity of 

 the splierical ooplasts adhere to them in such hxrge numbers that a sphere is some- 

 tiuies entirely coated with spermatozoids (see fig. 203 *). 



It has also been observed that the spherical ooplasts are set rolling by the 

 adherent spermatozoids, and are thus removed from the places where they pre- 

 viously lay stranded. The fertilizing effect exercised by the spermatozoids, one of 



Fig. 204.— Fertilization and Fruit-formation in Mucorini, Siphonacetx, and Florida^. 



'-* Conjugation and fruit-formation in Sporodinia grandis. *, « Vaucheria sessUis. ' Fruit-rudiment with trichogyne of 

 Vitdresnaya coccinea, 8 AutJieridia of the same plaut with spermatozoids in the act of abjunction. 9 Fruit of the same. 

 '-> X ISO ; s, « X 250 ; ', « x 400 ; » x 250. ('-9 after Bomet. ) 



which, as it appears, coalesces with the ooplasts, consists doubtless in a rearrange- 

 ment of molecules, and the first outwardly visible result of tliis i-earrangement is 

 the envelopment of the ooplast in a tough cell-membrane. The body must now be 

 considered to be a fruit — a unicellular fruit, which remains unaltered in a state of 

 rest for some time, but at length bestir:j itself, and stretching out attaches itself 

 firmly to the ground by means of root-like outgrowths. It then divides and gra- 

 dually develops into a fresh Fucus plant. 



In the two cases just described, the ooplasts are not fertilized till after they have 



