GESXERACE.E 329 



roundly ovate and entire ; the second pair are roundly oval with 

 a few crenatures ; and the third pair are cordate-ovate and 

 crenate. All the three pairs are developed close to the ground. 

 A very curious case presents itself in the different species 

 of Streptocarpus. The cotyledons are quite normal for some 

 time after germination. They are small or even minute, 

 orbicular, entire, sessile, and thinly glandular-hairy, or they 

 develop a very short petiole and become roundly ovate or 

 triangular, showing a midrib, but no other venation. The 

 different stages of growth after germination are well shown by 

 a seedling from S. Kexii crossed with S. lutea (fig. 568). 

 There are two or not infrequently three cotyledons. The 

 first leaf is developed from, one of them by intercalary 

 growth which sets in at the base of the lamina and con- 

 tinues for a considerable time. The original and true lamina 

 of the cotyledon is carried up on the apex of the leaf, 

 and the tip is therefore the oldest part. Finally it withers 

 and dies away, and the apex of the leaf dies away from 

 above downwards in the same fashion. In the early stage 

 the leaf as a whole becomes obovate, then broadly ovate 

 and obtuse. It retains this shape for some time ; but ulti- 

 mately becomes oblong or strapshaped with a more or less 

 cordate base, attaining a length of six to ten inches or more. 

 This type of Streptocarpus develops a rosette of leaves, the 

 second one of which seems to arise from the short, thick and 

 fleshy petiole of the first. S. Eexii var. floribundus is a strong- 

 growing form of the species. In its early stages it behaves in 

 the same way as the last, the first leaf being developed from 

 one of the cotyledons by intercalary growth at the base. 

 A rosette of leaves is ultimately formed, and when the 

 plants are strong the leaves vary from six to twelve inches or 

 more in length. The cotyledons of S. Dunnii are also perfect 

 and normal in the early stages, small, rotund and entire. 

 The only leaf the plant produces is developed from one of 

 the cotyledons and becomes oblong, narrowed toward the 

 apex, incurvi-penninerved, lobulate and dentate, cinereous 

 above from the presence of grey hairs, and rusty beneath with 

 reddish ones ; it varies from twelve to thirty-six inches in 

 length, and nine to twenty inches in width at the broadest part. 



