26 MAMMALS. 



the larger beasts would be forced to turn their attention 

 exclusively to the hen-house and the game-preserve. The 

 balance has been upset so often, and with such dire results, 

 that the present generation should be chary about experi- 

 ments of this kind, though even lately " lady-birds," as we 

 call them, have been introduced into a tropical island to 

 devour certain noxious native aphides, and there is a still 

 more recent movement afoot for acclimatising the nightin- 

 gale in America, as a pleasant change from the mocking- 

 bird. It would seem fair, however, to suppose that an 

 island without either rodents or carnivora would be an 

 ideal one for the agriculturist and farmer ; and New Zea- 

 land, indeed, is a case in point. In the ordinary course, 

 however, an island incapable of supporting so much wild 

 life has little in its soil to recommend it for such purposes. 

 It is, above all things, important that we should not 

 harbour any false notion that there is nothing more to be 

 learnt about our few mammals. From time to time we 

 hear the same plaint about the birds, yet book after book 

 appears ; and though it would be wide of the mark to say 

 that each new contribution to our bird-lore is full of original 

 matter, it is at least safe to aver that there is something 

 new, some trifling addition to our knowledge of the birds, in 

 almost every one. The food and reproduction of many of 

 our mammals are still matters of argument; and if an 

 opening for original investigation is sought, we need not 

 look further than the remarkable and still unexplained 

 mortality to which our shrews are subject at the end of 

 summer. 



