114 PARTS OF OVULE [CH. 



over to near the basal clialaza, and the axis of the ovule 

 curved like a horse -shoe or crescent, the ovule is campylo- 

 tropous, e.g. Cruciferse, Capparidacese, Resedaceae, Caryo- 

 phyllacese, Ohenopodiacese, &c. 



When the chalaza is carried forwards so as to invert 

 the ovule by the growth of the funiculus, which is fixed 

 along the side of the ovule, and brings the micropyle down 

 close to the apparent juncture with the stalk, the ovule is 

 anatropous. This is b}^ far the commonest form, and the 

 continuation of the vascular strand runs as a cord (Raphe) 

 up the side and parallel with the axis of the ovule. 



The place where the free part of the funicle i.e. the 

 stalk passes into the ovule as a whole, will break across 

 when the seed falls, and the scar which is left is called 

 the Hilum. In the orthotropous and campylotropous 

 ovules hilum and chalaza coincide, but in anatropous 

 ovules they do not the hilum is here separated from 

 the chalaza by the whole length of the ovule proper 

 i.e. the raphe. 



Some ovules are half-anatropous (Primulacese, Legu- 

 minosae, &c.), half-campylotropous, &c., but the special 

 terms coined for these cases are superfluous. 



Anatropous ovules are so common that differences re- 

 specting their orientation in the ovary are useful. If we 

 regard that side along which the raphe runs, it may be 

 turned towards or away from the ventral suture of the 

 carpel, and these characters have been employed in 

 distinguishing several closely allied plants or families 

 e.g. Euphorbia has the raphe ventral and Buxus has the 

 raphe dorsal, but in two species of the same genus (e.g. 

 Euonymus) we may have pendulous ovules with dorsal 

 raphe and ascending ones with it ventral : the point 

 depends largely on the displacement of the placenta of 

 the carpels, higher or lower as the case may be. Like 



