38 R. Marluth, Ph.D., M.A. — Some Adaptions, etc. 



the whole plant benefits indirectly from this arrangement. This case 

 shows very clearly how easily the scientist may fall into an error if he 

 judges from appearance only and does not base his opinions on 

 experiment. 



The attempt, which I have made in the preceeding pages, to group 

 these means of protection does not in the least imply, as already stated, 

 that the plants could be classified accordingly. On the contrary, 

 many of them combine various arrangements to secure the same result, 

 and it is very interesting to see how far this combination goes in 

 extreme cases. One example of this kind is furnished by the Naras. 



Unlike other cucurbitaceous plants, which usually possess a rich 

 foliage, it does not produce any leaves at all, forming with its trailing 

 twigs hedge-like shrubs on the sand-dunes. These twigs are protected 

 by a thick epidermis, strongly covered with wax and in its youngea 

 parts by hairs. The stomata are situated in deep grooves, which close 

 by an automatic arrangement when the loss of water becomes too 

 great. In addition to this, there is a water reservoir (hypoderma) 

 under the epidermis and a sponge-like tissue around the stomata through 

 which the air has to pass before it can reach the green cells. Finally 

 there are the hairs for the absorption of the water from the fog. Surely 

 one can hardly imagine anything more complete, and we can under- 

 stand how this plant is able to exist under such trying conditions, and 

 to produce numerous juicy fruits on which a whole tribe of natives 

 lives. 



What I have brought before you to-night is only a flying survey of 

 a large and for the greater part unexplored field. To treat such a question 

 satisfactorily and especially in a country with such a rich flora as ours, 

 would fill a volume. We should have no time for it, and I admit 

 with regret that I have not had the time to study it more than 

 superficially. Most of what I have said to-night is already the pro- 

 perty of science, but I have felt obliged to include it in my paper in 

 order to demonstrate the range of the subject. 



To the popular mind, a botanist is still a man who carries a big tin 

 on his back, collects all kinds of little weeds and calls them by long 

 names. But such work is only the preparation for the real study* It 

 is very interesting and also very useful to science, but, if the collector 

 stops short there, he is a botanist only to the same extent as the 

 sportsman who shoots birds and stuffs their skins is a zoologist. 



Concluding these fragmentary notes, I beg to express the hope that 

 more observers, who have taken up botany as a study or pastime, will 

 devote their attention to these questions, and by accumulating more 

 material from time to time will enable us gradually to obtain a better 

 insight into the relations which exist between vegetation and climate 

 in South Africa* 



