382 JOURNAL, BOMBAY NATURAL HIST. SOCIETY, Vol. XXIIl. 



the entire base, and the branches higher up which have a northern exposure 

 Here again the question is not one of base or end of a branch, but 

 one of exposure of the plant to its surroundings. In this case it is 

 more difficult to off"er an explanation. But the following points may have 

 a bearing on the phenomenon. The resting and sprouting buds of Tamarind 

 are well protected by a number of overlapping scale-leaves. The young leaves 

 are protected by large and red coloured stipules. The cell sap of the plant is 

 acid, and acidity* is looked upon as aff"ording protection under xerophytic 

 conditions by reducing transpiration. Thus it appears that new leaves do not 

 require to be protected as they do in the tree discussed above. The reten- 

 tion of the leaves towards the base after those at the crown have been 

 dropped does not appear to afford any advantage to the plant. It is 

 probably only a question of difference in maturity brought about by diffe- 

 rences in exposure. 



Another interesting point for study in this connection is that of the 

 season of leaf-fall. In a previous numbert of this Journal I described a 

 species of Saliv from this point of view. With regard to such seasonal 

 observations it has to be remembered that the seasons are not uniform by 

 any means all over the Presidency. This causes the same species of plants 

 to behave differently at a given time in different Districts. ThusinKanara 

 the appearance of new leaves may be marked a month or two ahead of the 

 same phenomenon in northern Gujarat. The differences in the time of leaf- 

 fall and " leaf-renewal " bring about variations in the length of period for 

 which trees remain bare. 



H. M. CHIBBEE. 



Agricultural College, Poona, 

 June 1914, 



• Warming:— OecoZogf?/ of Plants, Eng'lish Edition, 1909, p. 120. 

 t Vol. XXII, p.' 206. 



