292 ON SEEDLINGS 



embryo with broadly ovate or subtriangular cotyledons. The 

 terete radicle is slender and nearly twice as long as the coty- 

 ledons. The seed is attached ventrally to the placenta, and 

 is more or less angled by mutual pressure with its fellows. 



Seedlings. The cotyledons are all of simple types and vary 

 from subulate to linear, lanceolate, oblong, ovate, oval, and sub- 

 orbicular. Species with emarginate cotyledons occur only 

 where the latter are short and broad. The commonest type 

 is lanceolate or narrowly oblong in accordance with their shape 

 while yet in the seed. 



One of the most typical forms is represented by Lycoper- 

 sicum esculentum and Solanum Fontanesianum (fig. 544) 

 which have lanceolate cotyledons. In the first named the 

 cotyledons are hairy and one-nerved. In S. Fontanesianum 

 they are glabrous with the exception of the petiole. The coty- 

 ledons of S. Jacquinii are more broadly lanceolate, indis- 

 tinctly penninerved and finely pubescent. A species of 

 Capsicum (fig. 545) is notable for the great size of its coty- 

 ledons, the length of the petiole, and the three pairs of nerves 

 in the lamina ascending at an acute angle. 



A slightly different form is met with in Solanum Dulcamara 

 which has narrowly oblong, obtuse, one-nerved cotyledons. The 

 widest cotyledons noticed are those of Solanum quitoense, 

 which are broadly ovate and glandular-hairy on both surfaces. 



The cotyledons of species belonging to the tribes Cestrinese 

 and Salpiglossidse present a number of short, wide, and often 

 emarginate cotyledons more characteristic of the Scrophu- 

 larinese than of the Solanaceae proper, and owe their shape in 

 great part to that of the seed. Where emarginate cotyledons 

 occur they probably owe this modification to growth. Brow- 

 allia elata (fig. 549) presents a type very unlike the rest of 

 the Order. The cotyledons are oblate, that is, transversely 

 oblong. They are also very small, one-nerved and distinctly 

 emarginate. The first two leaves are small, oblong-ovate, 

 deeply and bluntly serrate. 



Lycopersicum esculentum, Miller. 



Primary root tapering vertically downwards or diverging at an 

 obtuse angle, giving off lateral adventitious rootlets. 



