FIG. 24. i, median section of a young oospore of 

 Achlya debaryana, showing female nucleus, centrosome, 

 and astrosphere, the entry of the sperm nucleus and 

 the presence of the receptive spot ; 2, portion of fig. i 

 more highly mag. ; 3, young oospores of A. debaryana 

 in which the wall is clearly visible. The mode of attach- 

 ment of the fertilisation tubes is illustrated. The rays 

 of the male astrospheres are directed outwards. (After 

 Trow. ) All highly mag. 



