1^2 LETTER XXXVII. 



given quite a new character to our gardens in summer 

 and autumn. 



The spines of Christ's-thorn, remind me that I have 

 never yet explained to you what spines really are. 

 What they appear to be, I need not tell you ; what 

 they are, you may easily learn from a bush of the Sloe, 

 on which they are sufficiently numerous. If you 

 examine them, you mil not fail to see that while a part 

 are merely sharp hard points, others have a few 

 buds upon their sides, and many more are invested 

 with leaves, or even flower-c}Tnes. They are, there- 

 fore, mere branches, with their points hardened and 

 sharpened. Upon the use of spines, I find the follow- 

 ing remarks by the late Professor Burnett : — " In 

 barren, uncultivated tracts of heath, or common land, 

 thorny plants abound, e. g. the Sloe (Prunus spinosa), 

 the Rest-harrow (Ononis spinosa), the Hawthorn 

 (Crataegus oxyacantha), the Buck-thorn (Rhamnus), 

 the Cockspur-thorn (Crataegus crus Galli), and many 

 others. These vegetables, when removed into gardens, 

 and cultivated with care, lose all their thorns, which so 

 thickly beset them when wild, and bear fruitful 

 branches in their stead ; becoming, as Linnaeus ex- 

 pressed it, tamed plants (Plantae domitae), instead of 

 the (Milites orj warriors, to use his language, that 

 they were before. Willdenow was the first who ex- 

 plained the rationale of this metamorphosis, the first 

 who shewed that thorns are abortive buds ; buds which 

 a deficiency of nourishment prevented becoming de- 

 veloped into branches, and which, when the requisite 

 supply of food is present, speedily evolve their latent 



