FERTILIZATION AND FRUIT-FORMATION IN CRYPTOGAMS. 



53 



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

 the spherical ooplasts adhere to them in such large numbers that a sphere is some- 

 times 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 eflfect exercised by the spermatozoids, one of 



Fig. 204.— Fertilization and Fruit-formation in Mucorini, Siphonacece, and Florideai. 



>-■» Conjugation and fruit-formation in Sporodinia grandis. 5, 6 Vaucheria sesdlis. ' Fruit-rudiment with trichogyne of 

 Dudiesnaya coccinea. 8 Antheridia of tlie same plant with spermatozoids in the act of abiunction. s Fruit of the same. 

 i-ixlSO; 5,6x250; ^ 8x400; 9x250. (7-9 after Bornet.) 



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

 ment of molecules, and the first outwardly visible result of this rearrangement 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 bestirs 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 



