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necessity for some peculiar means for this purpose is 

 seen from the difference in structure between these and 

 the woody evergreen shrubs and trees. The latter are 

 always supplied with apparatus (fresh living leaves) 

 necessary to make immediate use of the material offerred, 

 whenever a chance shower moistens the sandy soil of 

 the coast or makes its impress on the clay of the interior. 

 It is otherwise with an herb like Helichrysum. This does 

 not possess the strength of resistance residing in the 

 longer-lived thicker-leaved evergreens, its period of vege- 

 tation is limited, therefore the necessity for some special 

 means to make use of every particle of moisture which 

 is so grudgingly given, and which is so essential to its 

 welfare. This may be furnished by the arrangement of 

 the hairs of the leaf surface already described. We are 

 met at once here by an apparent contradiction in function : 

 That is, the very arrangement which we suppose for the 

 purpose of taking up water from the atmosphere, namely: 

 the thin-walled surface of the living hair-cells, offers, on 

 the other hand, just so much more surface from which 

 the water in the plant may be given off by transpiration. 

 Farther, the raised stomata contribute also to the same 

 end. If the object of the filz were simply to prevent 

 the escape of the water already taken up by the roots, 

 we would certainly not expect to find two such counter- 

 acting influences. The matter would be much simplified 

 by a lighter hair-covering without the living cells, and 

 with ordinary level stomata. But if, on the other hand 

 the plant is thus enabled to make use of the moisture 

 of the atmosphere, this apparent contradiction of function 

 is not so difficult of explanation. The covering formed 

 by the interwoven end cells of the hair, protects the leaf 



