

ME, A. "W. BENNETT ON CLEISTOGAMIC FLOWEBS. 277 



the pollen-grains are very few in number, of small size, and are 

 not connected together by threads, as is the case with those of 

 the perfect flowers. In the perfect flowers the anthers contain 

 bundles of raphides about the length of the pollen-grains ; but 

 these I never observed in the case of the closed flowers. A slight 

 but very interesting variation from the usual structure of the 

 closed flowers was observed in three instances. In all the re- 

 mainder of the very large number which I examined the brown 

 calyx broke away smooth from the receptacle as a regular conical 

 cap (as shown in fig. 14), not manifesting "Pi 15 



the least trace of a division into distinct ^A ^ 



sepals. In these three instances, however, 

 the cap exhibited a protuberance at one 

 side (fig. 15, J), clearly a rudimentary sur- 

 vival of the large spur-shaped nectary which 

 is so conspicuous in the perfect flowers, ilfcap-like calyx of cleis- 



Zparvkora, DC. (Northern Europe). togamic flower ordinary 



r i .. form. Id. The same, 



1 nave never been able to detect any w j t k rudiment of nee- 

 cleistogamic flowers in this species, which tary *• 

 comes up in great abundance and flowers very freely every year 

 in the Begent's Park Botanic Gardens, as well as in my own 

 garden. The plant seems invariably to produce abundance of 

 capsules which are undoubtedly the products of the perfect flowers, 

 as may be seen by the withered stamens which frequently adhere 

 to the apex. In no case have I found a capsule surmounted by a 



me 



M 



In- 



dependently of the much smaller size, the flower presents consi- 

 derable differences from those of these two species ; and there is 

 by no means the same difficulty in understanding how fertilization 

 can take place as there is in the case of I.fulva (see ' Journ. Linn. 

 Soc, Bot.' vol. xiii. p. 150). The whole flower does not drop in one 

 piece, as is the case in this latter species ; but first the sepals and 

 petals separately, and then the stamens, the filaments breaking 

 away at their base, while the five coherent anthers frequently re- 

 main attached to the stigmas for a considerable time. The pollen 

 is loose and powdery, and not attached together by threads. The 

 five stigmas are frequently expanded, and apparently in a recep- 

 tive condition, after the stamens and the rest of the flower have 

 been thrown off, a state of things which I have never seen in 

 either of the two other species, Mr. Henslow says that they are 

 self-fertilized. 



