26 ON SEEDLINGS 



as in Cerastium (figs. 23 and 56). In some of them, however, 

 such as the Pink itself (Dianthm) (fig. 22) and Tunica, they 

 are wide. 



Now in most genera, as in Stellaria, Spergularia, Cerastium, 

 &c., the seeds are laterally compressed ; the cotyledons con- 

 sequently lie transversely to the seed, and their width therefore 

 is limited by the thickness of the seed, as in fig. 56. The 

 case is, however, somewhat complicated by the fact that the 

 seed and embryo are both curved. 



On the other hand, in the Pink (fig. 57) the seeds are not 

 laterally but dorsally compressed, attached to the columnar 



FIG. 57. Dianthus Caryophyllus, x 15. 

 (In figs. 56 and 57 the letters a, b, and c, d indicate the directions of the sections.) 



placenta by the middle of the interior face, so that the coty- 

 ledons are straight, parallel to the seeds, and have in conse- 

 quence plenty of room to widen out. 



In Solanum the fruit is roundish, glabrous, indehiscent, 

 and many-seeded. The seeds are kidney-shaped, much 

 compressed laterally, and placed with their narrow edge to 

 the placenta, surrounded by a paler margin, glabrous and 

 white ; the hilum is small, and on the middle of the ventral 

 edge. The embryo is, in the mature seed, much curved, 

 embedded in, but lying near the outer edge of, the endo- 

 sperm. The radicle occupies the lower and narrow part of 

 the seed. The cotyledons are linear, not broader than the 

 radicle, curved, with their tips close to the hilum, and their 

 back to the placental axis, and at right angles to the plane of 

 the seed, the whole width of which accordingly they occupy, 



