328 UTILITARIAN ZOOLOGY 



doubtless due to the short-sighted policy of persecution meted 

 out to the unoffending bird by gamekeepers. As rats, shrews, 

 and voles are among its favourite articles of food, a few of these 

 voracious birds on an estate should be worth a ton of poison. . . . 

 The way in which gardener, farmer, and game-preserver unite 

 in persecuting this owl has been mentioned, and it is to be 

 doubted whether they would achieve a far different result were 

 they actually to breed and turn down rats and voles, of which 

 this bird must annually destroy hundreds of bushels." 



A great many birds render us invaluable service by destroying 

 vast numbers of injurious insects and insect-larvae. The Cuckoo 

 (Cucuhis canorus\ for example, is a great protector of fruit- 

 culture and forestry, for it greedily devours certain hairy kinds 

 of caterpillar, which most other birds refuse to touch. Among 

 other benefactors may be particularly mentioned Swifts, Swal- 

 lows, Martins, and Tit- Mice. In Germany various useful species 

 are provided with suitable nesting -boxes and wintering -boxes, 

 the size of the opening being adjusted to the particular kind 

 of bird. 



The African Secretary Bird (Serpentarius secretarius} is a 

 notable destroyer of poisonous snakes, and is domesticated by 

 the farmers of South Africa for the sake of its services in this 

 direction. 



There are also scavenging birds, such as Vultures, which in 

 hot countries discharge a most useful office. 



BENEFICIAL REPTILES (REPTILIA). Lizards are certainly to be 

 regarded as beneficials, for they feed largely upon injurious insects 

 and the like. Many Snakes are also useful, and some of them 

 render conspicuous service by preying upon small rodents. Some 

 species may even be domesticated on this account, as, e.g., the 

 Corn Snake (Coluber guttatus) in North America, and the Rat 

 Snake (Zamenis mucosus] in India. 



BENEFICIAL AMPHIBIANS (AMPHIBIA). All the members of 

 the class are beneficial, inasmuch as they live upon insects, 

 snails, slugs, and other destructive creatures. Ritzema Bos 

 states that . ..." in the research garden attached to the 

 Rouen entomological laboratory the snails were entirely exter- 

 minated in 1891, as a result of introducing a hundred toads and 

 ninety frogs ". The Toad in particular is one of the most useful 

 animals that can be put into a garden, effectually protecting 



