598 



THE POPULAR SCIENCE MONTHLY. 



cium), and other Himalayan species, which constitutes the highly 

 valued " rusot." 



Considered from the plant's standpoint, this bitter principle, so 

 abundantly present in its outer tissues, is doubtless to be re- 

 garded as a defense against gnawing animals, and as such, acces- 

 sory to the spines which can be effective as a protection only 

 against the larger animals which feed upon leaves. Thus, as 

 often happens with the plants of our pharmacopoeia, the very 

 means adopted for its preservation becomes the object of its 

 being destroyed for man's use. 



But the barberry has more to contend against than the 

 attacks of animals. As a native of regions visited by heavy 

 storms of snow and wind, its branch system (often eight to ten 

 feet in height), even though it be rid of its leaves through the 

 winter, must, nevertheless, be subjected to a very considerable 



F IG . 4. BEKBEKIS VULGABIS. Leafless branches, showing clusters of fruit and different forms 



of spines. 



mechanical strain. A glance at the vegetative organs of our 

 plant will show with what efficiency and economy of material 

 this bit of engineering is accomplished. 



First of all it will be noticed that there are two remarkably 

 different sorts of branches (compare Figs. 1 and 4). The one sort, 

 long, slender, and arching, are armed with the stout spines 

 already referred to ; while the others, originating from the axils 

 of these spines, remain very short, although bearing year after 

 year, through the summer, each a rosette of leaves. All who 

 have observed the effect upon our trees and shrubs of one of 

 those storms which load everything with snow and ice must 

 have seen that the plants which received least damage were 

 those in which there was either unusual stoutness of material or 

 else such an attitude and flexibility in the branches as enabled 

 them to bend readily under a load or other strain. Now, in the 

 branch system of the barberry bush we find all these character- 



