194 COLIN CLOUT'S CALENDAR. 



with this upward evolution from the green weed to the 

 solid tree we can trace a concomitant evolution from the 

 many-seeded berry like the raspberry or the blackberry 

 to the one-seeded stone-fruit like the sloe and the plum. 

 All those members of the rose family which have reached 

 this highest type of rose development, with shrubby 

 or tree-like stems and one-seeded fruits, form together 

 the almond sub-tribe of modern botanists. As in all 

 other cases, their succulent fruit-coverings are due to the 

 selective agency of birds and forestine animals, which 

 aid them in dispersing their large, hard, indigestible 

 seeds ; and the unusual size of these coverings shows at 

 once that they belong as a class to sub-tropical and tropical 

 regions, being adapted to large and active animal allies, 

 as our English wild strawberries, raspberries, and black- 

 berries are adapted to the smaller needs of northern 

 birds. 



Even among the plum or almond sub-tribe itself there 

 are many differences of size and color in the fruit, ac- 

 cording to the special localities where the various trees 

 have fixed their home. Our little black English bird- 

 cherry is a northern and Arctic variety ; it flourishes best 

 in Lapland and Scandinavia, becomes scarcer and scarcer 

 as we move down into Scotland and central Europe, dis- 

 appears altogether in southern England and Ireland, and 

 only penetrates into the south European and south 

 Asiatic regions along the snowy chains of the Cau- 

 casus and the Himalayas. The fruit is eaten chiefly 

 by the larger northern game-birds ; and it has never 

 been found worthy of systematic cultivation. Our 

 common sloe has a more southerly range and a bigger 

 fruit; but even it in the wild state is very sour and 

 little relished except by our native birds. In south- 

 eastern Europe and Central Asia, however, the sloes 



