STEMS AND THEIR APPENDAGES. 59 



The apj3end^gefi_of_iems are exceedingly numerous 

 and of diversified form and structure, and all are of 

 value, and of more or less importance in aiding us to 

 distinguish plants of the different classes, orders, genera, 

 species, and even the natural and cultivated varieties ; 

 but the space at my command will only admit of a 

 brief notice of the few with which the propagator must 

 necessarily become the most familiar. I will say, how- 

 ever, that he who aims to know plants must not think 

 that even the minutest character is unimportant, for 

 size is only a comparative term at best, and a thing may 

 be great among the small as well as among the large. 

 The most prominent appendages of stems are prickles, 

 as in the Nettle ; spines, as found on the canes of the 

 Black Easpberry, theTBlackberry and the Koses ; thorns, 

 as on the Hawthorn, the Honey Locust, and many of the 

 larger cactuses ; tendriis, as on the Clematis, Grape, 

 and many other climomg plants. Jjeaves, flowers, fruits 

 or seeds are other appendages. Prickles, "'Spines and 

 thorns probably ^aks^an active pa^rt in the general assim- 

 ilation of nutrients of the plant, atTeast while theylire 

 younglmd' growing, but what other pur^ose_jthey serve 

 in vegetable economy is noire^d^'^^^mmeSrim^iliej: 

 than they are distinguishing" cliaracTeristics among the 

 vast numbers which Nature employs in her always dif- 

 ferent and ever changing productions. To say that 

 plants are armed with spines or thorns as a protection, 

 .as is often asserted, has no foundation in fact, but it is a 

 purely sentimental idea, for the supposed protecting 

 organs do not protect against any natural enemy, for the 

 species most fully armed with the strongest spines and 

 thorns often perish from the attacks of some thin- 

 skinned and wholly defenseless little insect, while the 

 giant thorns of some trees often become the safe and 

 rather luxurious home of certain species of the ant. 



There are other appendages of stems which may not 



