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 eflPect exercised by the spermatozoids, one of 



Fig. 204. — Fertilization and Fruit-formation in Mucorini, Siphonaceoe, and Flaridece. 



^-* Conjugation and fruit-formation in Sparodinia grandis. *, « Vaucheria sessilis. ^ Fruit-rudiment with trichogyne of 

 Dudre&naya coccinea. 8 Antheridia of the same plant with spermatozoidg in the act of abiunction. 9 Fruit of the same, 

 i-i X 180 ; », 8 X 260 ; ', « x MO ; » X 250. ('-» after Bornet.) 



which, as it appeai-s, 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 bestiro 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 



