No. 492] NOTES AND LITERATURE 



815 



conifers is in no wise out of place in the environment of our mesopliytie 

 forests, for these are ecologically xerophytic for over half the year. 

 He also holds tlmt in the acicular leaf and the deciduous habit of some 

 of the northern conifers we liave more recent adaptations to the de- 

 mands of a xerophytic habitat, thus accounting for the present wide 

 distribution of this primitive group and its successful competition with 

 phylogenetically higher forms. 



The arguments of botli of tliese writers iire suggestive, and much of 

 the value of such discussions lies in the emphasis wliich they lay u[)()n 

 the necessity of approacliing these i)roblems with more precise mi^tliods 

 than have Iiitherto been employed. 



J. AiiinuK llAHins 



Notes on the Problem of Adaptation.— The Sfinc/hif/ Pmpn-ty of 

 the Giant Nettle tree. The gijint nettle tree, Laportea cjigns, a native 

 of Australia often attaining a height of over a hundred feet, lias long 

 been noted for the violence of its action. Its large juicy leaves are 



powerful stinging fluid. If the leaves be lightly bruslied these liairs 

 penetrate and break in the skin, causing pain wliicli gradually increases 



