206 COLIN CLOUT'S CALENDAR. 



hornbills, cockatoos, parrots, and other large bright-hued 

 fruit-eaters. Even in southern countries, however, there 

 are many small species, adapted to the smaller birds, 

 such as the common laurel and the Portuguese laurel, 

 both of which are true plums, with evergreen leaves to 

 suit a milder winter climate. 



Our own sloes must doubtless have branched off 

 from the common central one-seeded stone-fruit group 

 about the middle of the tertiary period. They are very 

 closely 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 white-thorn, which almost monopolises the 

 attentions of the fertilising 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 individuals 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 



