326 CLEISTOGAMIC FLOWERS. Chap. VIII 



this is not the case, according to Von Mohl, with the 

 cleistogamic flowers of other Leguminosse. Five of 

 the stamens are destitute of anthers, and alternate with 

 the five thus provided. The two cells of the anthers 

 are minute, rounded and separated from one anothei 

 by connective tissue; they contain but few pollen- 

 grains, and these have extremely delicate coats. The 

 pistil is hook-shaped, with a plainly enlarged stigma, 

 which is curled down, towards the anthers ; it there- 

 fore differs much from that of the perfect flower. 

 JDuring the year 1867 no perfect flowers were pro- 

 duced, but in the following year there were both 

 perfect and cleistogamic ones. 



Ononis minutissima. — My plants produced both per- 

 fect and cleistogamic flowers ; but I did not examine 

 the latter. Some of the former were crossed with 

 pollen from a distinct plant, and six capsules thus ob- 

 tained yielded on an average 3 ■ 66 seeds, with a maxi- 

 mum of 5 in one. Twelve perfect flowers were marked 

 and allowed to fertilise themselves spontaneously under 

 a net, and they yielded eight capsules, containing on 

 an average 2 '38 seeds, with a maximum of 3 in one. 

 Fifty-three capsules produced by the cleistogamic 

 flowers contained on an average 41 seeds, so that 

 these were the most productive of all ; and the seeds 

 themselves looked finer even than those from the 

 crossed perfect flowers. According to Mr. Bentham 

 0. parvijlora likewise bears cleistogamic flowers ; and 

 he informs me that these flowers are produced by all 

 three species early in the spring ; whilst the perfect 

 cmes appear afterwards, and therefore in a reversed 

 order compared with those of Viola and Oxalis. Some 

 of the species, for instance Ononis columnse, bear a 

 fresh crop of cleistogamic flowers in the autumn. 



Lathyrus nissolia apparently oflers a case of the first 



