cxcii Journal of the Asiatic Society of Bengal. [N.S., XIII, 



between the species resulted in seed production. It is proved that the 

 banana fruit swells without pollination but that of M. superba does not. 

 The influence of pollen of a red variety did not show when used to 

 fertilise a yellow variety of banana. The origin of the edible pulp is 

 stated. An interesting variant of the banana, producing in normal 

 circumstances 25 ** hands," is described and its possible heritability dis- 

 cussed. 



Observations on Pollination in Alysicarpus. — By K. Cherian 



Jacob. 



The whole genus Alysicarpus possesses in the flower an interesting 

 explosive mechanism for the sudden discharge of pollen into the air or on 

 an insect-visitor. The Indian species of Alysicarpus can be divided into 

 two groups, one with glumaceous calyx enclosing the corolla and the other 

 with small calyx reaching to only about half the length of the corolla. 

 A. rugosus — a representative of the glumaceous calyx group explodes its 

 mechanism only when visited by Nomia oxybeloides. Unexploded flowers 

 do not set fruits at all. A. vaginalis — a representative of the small calyx 

 group— is capable of exploding its mechanism without the help of any 

 external agency and throws a cloud of pollen upwards showering the same 

 on the flowers of the neighbouring plants. The usefulness of this adapta- 

 tion in securing cross-pollination is evident from the fact that this specie 

 possesses a gregarious habit. In fact, in a patch of ground 7 inches in 

 diameter, the branches of 9 different plants could be traced and one 

 square foot of ground covered by the plant showed on an average about 

 90 different inflorescences. 



So, in the above we have an instance of a common plant which en- 

 sures cross-pollination by the spontaneous explosion of its flowers and 

 without the help of any external agency. 



The irritability of the Bladders in Utrirulnria. II. Structure 



and Mechanism.— By T. Ekambaram. 



1. The structure of the irritable hairs is described and compared with 



those of aldrovanda. 



~. ±*art of the ridge surrounding the mouth is shown to act as a 

 spring hinge which draws down or pushes up the valve. 



3. The positions assumed bv the valve before and after irritation is 

 shown to be due to a difference in the dimensions of the two layers of 

 cells that make up the valve. The mechanism is explained. 



t' ^u e [ unctlon of the margin is also partly explained. 

 5. I he hungry condition of the bladder is brought about by all the 

 tissues becoming turgid. 



« 4 *' T £ e f e3llU °* irritation is taken to be a momentarv loss of to*tF 

 dity in all the tissues. 



Variation in some Himalayan liverworts.— By 8- R. Kashyap. 



Four species of thallose liverworts are described showing a consider- 

 able degree of variability. 



1 . Targionia hypophylla. Already worked out by the writer and also by 

 Miss O'Keefe. (Xew Phytologist, Vol. XIII. Nos. 6 and 7 and Vol. XIV, 

 No3. 4 and 5). The chief features of interest here are :— (a) the presence 

 of anthendia on the usually described disc-like ventral snoots, also on 

 shoots having more or less well-developed wings and lastly even on the 

 mam shoot m the form of a dorsal cushion, (b) The different degrees of 

 development of the teeth in the involucral valves. In some specimens 

 they are well- developed throughout the whole margin of the valves, m 

 others feebly developed or quite absent on the greater part of the margin. 



