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allied in every respect to the cherries, which represent 

 only a somewhat more southerly variation of the same 

 ancestral stock. As bushes of the northern thickets, 

 however, the sloe-trees have either acquired or retained 

 the habit of producing short abortive pointed branches 

 along the stems, which act as defensive thorns to prevent 

 the attacks of the larger animals. They blossom very 

 early in spring, before the leaves are out, for they have 

 a comparatively large fruit to perfect before autumn in 

 the precarious sunshine of an English summer ; and 

 besides, they have to anticipate the more attractive 

 w T hite-thorn, which almost monopolizes the attentions of 

 the fertilizing bees in its own rather later flowering 

 season. The material for the blossoms is already laid by 

 in the permanent tissues of the bush, and therefore the 

 blackthorn can flower equally well at any time, as far as 

 resources go. But those bushes which flower earliest 

 must always have best succeeded in alluring bees, and 

 have fared best in setting their fruits, while later individ- 

 uals could not compete with the lush-scented and 

 thicker-blooming may, and could not always ripen their 

 seeds before the advent of the autumn frosts. Hence the 

 habit of early blossoming has become ingrained in the 

 race by the constant survival of those families which pos- 

 sessed it, and the constant dying-out of those families 

 which delayed their bloom till the may was out. 



With us, the sloes are small, hard, and very acrid ; 

 but in southern Europe and central Asia, where the con- 

 ditions are more favorable for the production of large 

 and juicy fruits, they become longer, sweeter, pulpier, 

 and less bitter ; the trees grow taller, with more of a 

 distinct trunk ; and, as a natural consequence, they tend 

 rather to lose the thorns, which are only serviceable to 

 small straggling bushes, liable to be trodden under foot 



