102 VARIOUS USES OF SHELLS chap. 



bestowed by the Emperor upon high officers whose duties oblige 

 them to take voyages by sea. The Viceroy of Fukhien probably 

 possesses one of these shells in virtue of his jurisdiction over 

 Formosa, to which island periodical visits are supposed to be 

 made.^ 



Shells appear to be used occasionally by other species besides 

 man. Oyster-catchers at breeding time prepare a number of 

 imitation nests in the gravel on the spit of land where they 

 build, putting bits of white shell in them to represent eggs.^ 

 This looks like a trick in order to conceal the position of the 

 true nest. According to Nordenskjold, when the eider duck of 

 Spitzbergen has only one or two eggs in its nest, it places a shell 

 of Buccinum glacials beside them. The appropriation of old 

 shells by hermit-crabs is a familiar sight all over the world. 

 Perhaps it is most striking in the tropics, where it is really 

 startling, at first experience, to meet — as I have done — a large 

 Cassis or Turbo, walking about in a wood or on a hill side at 

 considerable distances from the sea. A Gephyrean QPhascolion 

 stromhi^ habitually establishes itself in the discarded shells of 

 marine Mollusca. Certain Hymenoptera make use of dead shells 

 of Helix hortensis in which they build their cells.^ Magnus 

 believes that in times when heavy rains prevail, and the usual 

 insects do not venture out, certain flowers are fertilised by snails 

 and slugs crawling over them, e.g. Leucanthemum vulgare by 

 Limax laevis^ 



Mollusca as Food for Man. — Probably there are few coun- 

 tries in the world in which less use is made of the Mollusca as 

 a form of food than in our own. There are scarcely ten native 

 species which can be said to be at all commonly employed for 

 this purpose. Neighbouring countries show us an example in this 

 respect. The French, Italians, and Spanish eat Natica, Turho, 

 Triton, and Murex, and, among bivalves, Donax, Venus, Litlio- 

 domus, Pholas, Tajjes, and Cardita, as well as the smaller 

 Cephalopoda. Under the general designation of clam the Ameri- 

 cans eat Venus mercenaria, My a arenaria, and Mactra solidissiyna. 

 In the Suez markets are exposed for sale Stromhus and Melon- 

 gena, Avicula and Cytherea. At Panama Donax and Solen are 



1 Nature^ xxxi. 1885, p. 492. 



2 W. Anderson Smith, BpiiderJoch, p. 173. 



3 Dominique, Feuill. yat. xviii. p. 22. ^ SB. Nat. Fr. Berl. 1889, p. 197. 



