WILD ANIMALS BENEFICIAL TO MAN 325 



Three methods of sponge-fishing are practised in the Medi- 

 terranean, according to the depth of water. Where this is very 

 shallow a five-pronged fork is employed, beyond the range of 

 which (up to about 30 fathoms) diving is resorted to, while speci- 

 mens growing in comparatively deep water (up to 200 fathoms) 

 are dredged. The yield of the Italian sponge-fisheries for 1902 

 was worth ,24,720. 



WILD ANIMALS BENEFICIAL TO MAN ON ACCOUNT OF 



THEIR HABITS 



From the economic stand-point many wild forms are of very 

 considerable benefit to man, because they prey upon other crea- 

 tures which are injurious to himself, his stock, and his crops. 

 To some such animals we should extend the " protection " which 

 they deserve at our hands, while for others equally beneficial 

 (e.g. certain insects) we can do nothing in that direction. And 

 it should be remembered that without very full knowledge it is 

 very risky either to mercilessly persecute native forms, or to* intro- 

 duce species from other countries. The result of the ruthless 

 slaughter of bats in a particular locality has been elsewhere men- 

 tioned (see vol. ii, p. 346), while the introduction of rabbits into 

 Australia has led to unexpected and undesirable consequences. 



Certain other wild species deserve the name of " beneficials " 

 because they promote the health of mankind, or unconsciously 

 assist in the work of agriculture, &c. 



It will sufficiently serve the purposes of this work if the 

 general nature of our indebtedness to certain groups of animals 

 is indicated in a few paragraphs. For this and the other aspects 

 of applied natural history readers who may be interested are 

 specially recommended to consult Theobald's First Report on 

 Economic Zoology (1902), one of the publications issued under 

 the auspices of the British Museum (Natural History). This 

 is rendered particularly valuable by the Introduction ("A Classi- 

 fication of Animals from the point of view of Economic Zoology ") 

 written by Ray Lankester. The word " beneficials " is applied by 

 him in a somewhat narrower sense than it is here. 



BENEFICIAL MAMMALS (MAMMALIA). The destructiveness of 

 Foxes, Weasels, Stoats, and the like, is so obvious, that the idea 

 of their being "beneficials" would be scouted by many, though 



VOL. IV. 116 



