. VIIJ. CLEISTOGAMIC FLOWERS. 329 



were thrown up by some plants in my green-house 

 bore only cleistogamic flowers. The petals of small 

 size remained permanently closed over the repro- 

 ductive organs, but their white tips could just be 

 seen between the almost completely closed sepals. 

 The pollen, which was scanty in amount, but not so 

 scanty as in Viola or Oxalis, remained enclosed 

 within the anthers, whence the tubes proceeded and 

 penetrated the stigma. As the ovarium swelled the 

 little withered corolla was carried upwards in the 

 form of a cap. These cleistogamic flowers produced 

 an abundance of seed. Later, in the season perfect 

 flowers appeared. With plants in a state of nature the 

 flowers open only in the early morning, as I have been 

 informed by Mr. Wallis, who particularly" attended to 

 the time of their flowering. In the case of D. Anglica, 

 the still folded petals on some plants in my green- 

 house opened just sufficiently to leave a minute 

 aperture ; the anthers dehisced properly, but the 

 pollen-grains adhered in a mass to them, and thence 

 emitted their tubes, which penetrated the stigmas. 

 These flowers, therefore, were in an intermediate con- 

 dition, and could not be called either perfect or 

 cleistogamic. 



A few miscellaneous observations may be added 

 with respect to some other species, as throwing light 

 on our subject. Mr. Scott states * that Eranthemum 

 amhiguum bears three kinds of flowers, large, con- 

 spicuous, open ones, which are quite sterile, others 

 of intermediate size, which are open and moderately 

 fertile and lastly small closed or cleistogamic ones, 

 which are perfectly fertile. Ruellia tiiberosa, likewise 

 one of the Acanthaceae, produces both open and cleis- 



'Journal of Botany,' London, new series, vol. i. 1872, pp. 161-4. 



