1914] 



GETM AN— OOGENESIS IN HORMOSIRA 



267 



It will be recalled that the several genera of the Fucaceae, in 

 their oogenesis, present an interesting illustration of recapitula- 

 tion. Of the members of this family which have been investigated, 

 all except Sargassum show three mitoses in the oogonium, resulting 

 in the formation of eight nuclei. In the genus Fucus, all the nuclei 

 are centers for the formation of the eggs. In another genus, 



Fig. 3. — Hormosira Banksii var. Sieberi: young plant 



Ascophyllum, OLTMANNS found four functional eggs. In Pehctia 

 he found that only two eggs mature and that the other six nuclei 

 abort. In Himantkalia, Oltm vnxs (8) found only one egg, and 

 Yamaxouchi has observed the same condition in Cystosira. In 

 both cases the other seven nuclei degenerate. In Sargassum 

 fill pendulum, Miss Simons (9) finds no mitosis after the formation 

 of the oocyst, and therefore the 2X number of chromosomes should 



