AND THE DISEASES OF PLANTS. 293, 



Caroline. Is it not singular that these two last degen- ( 

 erations, resulting from a similar cause, should be so dif- 

 ferent in their effects ? In the thorn the food hardens 

 without extending the shoot, whilst in the tendril it is ex- 

 tended to a considerable length, and is extremely flexible 

 and slender. 



Mrs. B. Nature has so contrived it (though by means 

 which are unknown to us,) no doubt, with a view to pro- 

 vide support for climbing plants, which are too weak to 

 bear the weight of their produce ; and where no such as- 

 sistance is required, she has converted the abortive shoot 

 into an arm of defence. 



Emily. Would, then, these plants have fewer tendrils 

 and thorns, if transplanted into a richer soil ? 



Mrs. B. No doubt; because a greater number of 

 young shoots would be brought to perfection. M. De 

 Candolle transplanted a wild medlar-tree, covered with 

 thorns, into his botanical garden, and in the course of 

 three years rot a single thorn was to be seen upon it. 



Emily. Yet I have never observed that the rose or the 

 gooseberry bush lost any of their thorns by cultivation. 



Mrs. B. They are not thorns, but prickles, which 

 grow upon the rose, the bramble, the gooseberry, and many 

 other plants ; and these are quite of a different nature. 

 The prickle is a natural appendage, which has no connec- 

 tion with the wood ; it springs from the bark, and is peeled 

 off with it ; and since it does not result from the degen- 

 eration of any organ, it is not susceptible of being dimin- 

 ished by cultivation. 



The peduncle of the grape terminates in a tendril, when 

 the vine is loaded with as many clusters of fruit as it can 

 bring to maturity. But in a very favorable soil, more 

 grapes would be produced, and this transformation of the 

 fruit-stalk takes place later, and probably less frequently. 



Caroline. And may not monstrosity of organs be pro- 

 duced by plants having too much nourishment ? 



Mrs. B. Certainly ; it happens, if the nourishment, in- 

 stead of being equally disseminated throughout the plant, 



1582. What question does Caroline ask in reference to these two last 

 degenerations'? 1583. With what view does Mrs. B. suppose nature 

 has so contrived this singular phenomenonl 1584. What is related of 

 Candolle respecting a wild medlar tree 1 ? 1585. What is said of the 

 prickles which grow on the rose, the bramble, and the gooseberry 1 ? 1586, 

 What is said of the vine, when the peduncle terminates in a tendril 1 ? 



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