S3 /'Hey Some Interrelations of Plants and Insects. 



form the stigmatic tube. A transverse section anywhere about 

 the middle will show that each of the six longitudinal sections 

 contains a row of ovules within an ovarian cell. More strictly. 

 the ovules are in pairs, as there are but three primary sections 

 or carpels, divided by three primary divisions or dissepiments. 

 Figure 4 shows a transverse section of one of these primary 

 divisions or carpels which well indicates the position of the ovules 

 (a), the funiculus (6), the placenta (V), and the ovarian cell (//). 

 As the fruit enlarges, the three secondary dissepiments narrow 

 and coalesce, while the other three widen, so that the pod be- 

 comes practically three-lobed and the seeds are more distinctly 



FKI. 4. Transverse section of one of the carpels of Yueea pistil : a, ovule; l>, t'miicu- 

 111$: c, placenta; rl, ovarian oell ; e, fihro-vascular bundles; /, fihro-vascular tissue: ;/ 

 primary dissepiment X 9. 



in pairs, the inner side straight and the external quite convex. 

 In oviposition the young fruit is pierced just within the ridge 1 in 

 the depression occupied by the stamens, and almost always on 

 the side of one of the primary or deeper divisions, where the 

 walls are thinnest, so that the ovipositor enters the ovarian cell 

 at the external or rounded side of an ovule and does not ordi- 

 narily touch the ovule itself. Rarely, however, the ovipositor 

 penetrates the ridge and passes between two of the ovules, or 

 sometimes even penetrates one, this last case being, however. 

 quite exceptional. 



" The egg is an extremely delicate thread-like structure, aver- 

 aging l.. r > mm. in length and less than 0.1 mm. (Fig. 1, ///, //, <>) 



