THE PISTIL. 99 



FIG. 207. 



Chalaza. 



Base of Nucleus. 



Primine ... _ 



--Rhaphe 



,-. ,. r- \ \ :! **.-:* f-vr.vT J.W.M.^/AA^ 



Secundme 



Nucleus.-- --N 



MICROPYLE. The opening in the coats of an ovule, 

 or seed (Figs. 206 and 207). 



NUCLEUS. The substance contained within the 

 sacs, in which the embryo is formed (Figs. 206 and 

 207). 



RHAPHE. The connection between the base of the 

 nucleus and the base of the ovule. In Fig. 206 the 

 rhaphe is short, and concealed within the ovule, but 

 in Fig. 207, where the position of the nucleus is so 

 changed as to bring its base round to the apex of the 

 ovule, the rhaphe is visible, and extends along one 

 side, still connecting the base of the nucleus with the 

 base of the ovule. 



CHALAZA. The place where the coats and nucleus 

 grow together. 



HILUM. The scar left by the separation of a seed 

 from its placenta. 



It is not supposed that pupils will find all these 

 parts of the ovule in plants. Some of them are usu- 

 ally discernible, and they may all be understood in 

 their proper relations by studying the diagrams. 



