1917. j The Fourth Indian Science Congress. cxci 



The genus Oxalis is geographically very ui table and a discussion of 

 the distributional history of the remaining species is prompted by their 

 now recorded presence as wild plants in India. 



In conclusion the authors call for the co-operation of systematist 

 and others engaged in botanical pursuits in recording the arrival and the 

 success or failure of exotics in establishing themselves, in India. 



Note on a Malformation of a Pine-apple {Ananas). — H\j P. F. 



Fyson. 



A malformation of the Pine-apple is described in which the receptacle 

 had grown out laterally and bore a very large number of small flowers in 

 an irregular formation, recalling on a large scale the Cockscomb variety of 

 the cultivated Celosia. The tissues were found infested with an intra- 

 cellular plasmodium, to which the fasciation was in all probability due. 



Note on the Killing off of a True Water Plant {Scirpus micro- 

 witus) by a Plant of firm though moist land (Ammania 

 Rotundifolia) .—By P. F. Fyson. 



Scirpus micronatus L. which forms a dense fringe round the shores of 

 the lake at Kodaikanal has been dying off at certain depths, while grow- 

 ing well in deeper as well as in shallower water. Where this happens the 

 roots are surrounded by a dense matting of thin stems and narrow leaves 

 which though different in appearance have been traced to the Ammania 

 rotundifolia Ham which grows on the adjoining bank. 



Oecological Notes on the Flora of the Pulney Downs.— By 



P. F. Fyson. 



Attention is drawn to certain plant associations and special adapta- 

 tions exhibited. 



The Inflorescence and Flowers of the Banana (Musa sapientum) 

 and its wild relative (Musa superba) — By W. Burns, 

 V. G. Mandke and P. J. Dhunbhttra. 



The paper describes a research in progress, the aims of which are :— 



(1) to observe accurately the development and morphology of the in- 

 florescence and flowers in Musa sapientum and Musa superba ; 



(2) to study the phenomena of pollination and fertilisation in these 

 species ; 



(3) to study the seed production of M. superba and the non-produc- 

 tion of seed in M. sapientum. 



The transition-leaves that herald the appearance of the inflorescence 

 are described and a theory put forward to account for their fewness in 

 M. sapientum and their abundance in M. superba. Variations in the 

 bracts both as to shape and axillary flowers are described. The various 

 organs of the several types of flowers are described and special atten- 

 tion is given to the perianth and androecium. It is concluded that the 

 flower of Musa is undoubtedly developed from the usual monocotyedon- 

 ous type, and that its present form is due to (a) suppression of the 

 posterior stamen, (6) the reduction of the two anterior members of the 

 inner whorl of the perianth and their fusion with the three similarly re- 

 duced members of the outer whorl, and (c) the development of the re- 

 maining member of the inner whorl as a hood-like body. 



Sections of the ovules of both species are described. The erabryosac 

 contents have not yet been clearly made out. Crosses made both ways 



