94 



THE AMERICAN BOTANIST. 



baricum, Eriodendron aufractuosum, Spondias, Mangi- 

 fera, Stereospermum chelenoides, Ficus Arnottiana, Derris 

 robusta, Careya arborea, Ficus religiosa, Cratfeva Rox- 

 burghii, and very many other species give a characteristic 

 barren appearance to the arborescent vegetation. The 

 deciduous trees seem, therefore, only to recognise one hot 

 dry period of three to four months as against the alter- 

 nating dry and wet months of the remainder of the year. 

 Further, every tree of Termimalia catappa undergoes a 

 complete change of leaf during the dry part of each mon- 

 soon, and other species, I suspect, undergo foliar repletion 

 twice every year. In addition to these we have some spe- 

 cies, not native, which though they drop all their leaves 

 and regain complete foliage at one time of the year, also 

 suffer partial falls and productions at other times of the 

 yean 



Instances of acclimatisation are well known, but there 

 are also some species which do not appear capable of 

 readily accommodating themselves and drop and reduce 

 leaf during any month of the year. This is characteristic 

 of Cedrela Toona^ planted in the up-country and a native 

 ut Australia. There are some species which though in the 

 Peradeniya districts are quite deciduous, yet in the more 

 equable climate of Java are quite evergreen. 



Though the climatic effects are obvious on many of 

 our species, there are several trees which behave in a man- 

 ner indicative of personal or interval factors being at 

 work. Many species drop their leaves and regain full foli- 

 age at a time w^hich appears decidedly disadvantageous. 

 Many retain full possession of their foliage or put forth 

 the whole of the young tender leaves at a time when the 

 physical condition favour maximum transpiration. These 

 species may be less plastic to the climatic forces, or it may 

 be that they can achieve their ends in opposition to still 

 more severe external forces. 



If one selects trees of Lagerstroemia Eos-regina^ Bri- 

 delia retusa, or species of Canarium or Palaqmum, he will 

 find that though they exist alongside each other under 



