44 



SEX AND HEREDITY 



tube, which then passes on between the cells of the style 

 (Fig. 24). Traversing the style in this way, it reaches 

 the cavity of the ovary, where it may be conducted 



FIG. ->5. 



Median section of an ovule of the Marsh Marigold (Caltha), showing the egg- 

 apparatus (f.rt) deeply seated, and consisting of the single ovum, which projects into 

 the embryo-sac, and two adjoining cells (synergidae). /=fuiiieulus ; r/; = chalaza ; 

 ; mi( -ropyle ; HUC-- - nucellus ; o. int.; i. int. = outer and inner integuments ; 

 /;j = central fusion nucleus ; unf antipodals. The structure here shown is very 

 general for ovules of Flowering Plants. ( x no.) 



mechanically by directing hairs to the apex of the ovule. 

 It there enters the narrow channel of the micropyle, and 

 makes its way to the ovum itself (Fig. 27, B). It may be 

 a question what are the influences which direct che last 



