180 THE BOTANICAL MAGAZINE. LVo<. xxxm. No. 39:^. 



mother-cell bulges out at a point, and a circular opening of 

 about 2 (J. in diameter is formed at its top. The antheridium 

 bursts at the opening" and the whole content is discharged. 

 The emptied antheridium recalls what has been delineated 

 by Magnus^^ as the zoosporangium of Chyrtidium sphacellaram 

 Kny. I was not able to closely observe the healthy form of the 

 swimming spermatozoids. I regret to say that their normal 

 shape, the number of flagella, which arc undoubtedly present, 

 and other morphological details, can not be discussed here. 



Several oogonia are generally found in one sporeling. 

 Their position in a filament is not fixed. In the majority of 

 cases, they a.re in a series beginning from the initial cell or at 

 the base of a branch as well. Thcj^ are, as a rule, generated 

 in the same individual with the antheridium (Fig. 9, 10). 



The oogonia maj' be recognized by an unusual intense 

 colour of the chromoplasts and by a rich granular substance in 

 them. Soon the periclinal surface bulges out towai'ds one side, 

 in a conical shape with blunt top. These conical mounds are 

 septated at the base, i. e,, along the periclinal surface of the 

 mother-cell. The^'' grow larger into spherical bodies and 

 become constricted at the septal points. These at last come off 

 their mother-cells as free oospores (Fig. 11). In what manner 

 they have been fertilized I have nothing to say at present, I 

 could not see an3' spermatozoid attached to the oogonia. It 

 will be interesting to the reader to call attention to the fact 

 that certain forms of Leptonema fasciculatum var. uncinatum 

 Reinke illustrated in " Atlas der deutschen Meeresalgen," Plate 

 9, fig. 5, 8 and 9 have some resemblance to this stage. 



The oospores are spherical bodies with a prettj' thick 

 membrane. They measure almost invariably about 10 /< in 

 diameter. A thick chromoplast lines a greater part of the inner 

 surface of the wall, jind at the center of the cell-cavit}' a single 

 nucleus is found. Fine, colourless granules are richly found in 

 the plasm. (Fig. IvS, 11). 



1) Magnus: Exped. zur physikal.- chem. n. hii 1- Uiiters. d. Nordsee iin 

 Somnier 1872. III. Die hot. Ergebn. Taf. r,9, fig. 20. 



