Chap. VIII. IMPATIBNS. 327 



stage in the production of cleistogamic flowers, for on 

 plants growing in a state of nature, many of the flowers 

 never expand and yet produce fine pods. Some of 

 the buds are so large that they seem on the point of 

 expansion ; others are much smaller, but none so small 

 as the true cleistogamic flowers of the foregoing 

 species. As I marked these buds with thread and 

 examined them daily, there could be no mistake about 

 their producing fruit without having expanded. 



Several other Leguminous genera produce cleisto- 

 gamic flowers, as may be seen in the previous list ; but 

 much does not appear to be known about them. Von 

 Mohl says that their petals are commonly rudimentary, 

 that only a few of their anthers are developed, their 

 filaments are not united into a tube and their pistils 

 are hook-shaped. In three of the genera, namely Vicia, 

 Amphicarpasa, and Voandzeia, the cleistogamic flowers 

 are produced on subterranean stems. The perfect 

 flowers of Voandzeia, which is a cultivated plant, are 

 said never to produce fruit ; * but we should remember 

 how often fertility is affected by cultivation. 



Impatiens fulva. — Mr. A. W. Bennett has published 

 an excellent description, with figures, of this plant.f 

 He shows that the cleistogamic and perfect flowers 

 differ in structure at a very early period of growth, so 

 that the existence of the former cannot be due merely 

 to the arrested development of the latter, — a conclusion 

 which indeed follows from most of the previous de- 

 scriptions. Mr. Bennett found on the banks of the Wey 

 that the plants which bore cleistogamic flowers alone 

 were to those bearing perfect flowers as 20 to 1 ; but 



* Correa de Mello (' Journal African plant, wMoh is sometimes 



Linn. Sue. Bot.' vol. xi. 1870, p. cultivated in Brazil. 



254) particularly attended to the + 'Journal Linn. Soc. But.' vol. 



flowering and fruiting of this xiii. 1872, p. 147. 



