CIvEJISTOGAMOUS I^LOWElRS 199 



lanceolate, to spatulate growth between the two fertile stamens.' 

 It was thought at the first^ that this third body was a sterile 

 stamen. More careful examination of flowers of Viola cucullata 

 Ait, {Viola obliqua Hill) showed that this process of greater or 

 smaller size is exactly alternate with the two stamens and also 

 alternate with the lower sepals. Specimens were found in which 

 the broader expanded portion was violet in color and even had 

 a trace of spur-like sac. It is therefore the reduced lower petal 

 or keel. This becomes all the more evident when, as is usually 

 the case, we find that the other 3 stamens and the other 

 4 petals are found exactly in their relative positions with respect 

 to the very unequal sepals. These stamens and petals are, however, 

 so far reduced or atrophied as to be represented only by small 

 globular-tipped gland-like bodies. 



In not a few instances Viola cucullata Ait. shows also one or 

 two other petals, one of these often colored blue oftener white. 

 These correspond by position to the lateral ones of the spring 

 flowers of the same plant. Another notable peculiarity of this 

 violet is that occasionally one finds a small stiped ovary within 

 the well developed seed capsule. This ovary within another, 

 reminds us of the somewhat similar growth of the "navel" orange. 

 The small long styled ovary is developed inside from the middle 

 of the torus, and the style with its broad spoon-like stigma reaches 

 well towards the apex of the outer one which is by this time well 

 "run to seed." Often the style of the inner ovary is bent back 

 upon itself the whole being often nearly 6-7 mm. long and appar- 

 ently devoid of ovules. 



Cleistogamous flowers of violets being quite easily obtained 

 and at the same time available during most of the summer and 

 fall, may very appropriately serve teachers in demonstrating the 

 germination and growth of pollen tubes into the ovary. The 

 stigmas of these flowers being only openings at the end of the short 

 curved style, and devoid of sticky exudation, the pollen grains 

 often germinate in or near the anthers sending their tubes from 

 the stamens to the ovary. Even in old cleistogamous flowers in 

 which, as in Viola cucullata, the capsule is already over a centi- 

 metre and even il4. cm. long, the cotton-like tufts of germinating 

 pollen tubes may be seen with the naked eye near the top of the 



1 Nieuwland, J. A., Am. Mid. Nat. III. p. 85, (1913). 



2 1. c. p. 91. 



