326 CLEISTOGAMIC FLOWERS. CHAP. VIII. 



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 expan- 

 sion; 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, 

 Amphicarpaea, and Voandzeia, the cleistogamic flowers 

 are produced on subterranean stems. The perfect flow- 

 ers 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 



* Cornea de Mello ('Journal African plant, which is sometimes 



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



254) particularly attended to the t 'Journal Linn. Soc. Bot.' vol. 



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



