WILD LIFE OF ORCHARD AND FIELD 



of all the species of Helicarion he met with showed 

 signs of this self-mutilation; and furthermore that 

 there seemed a tendency among various other spe- 

 cies of snails of the Philippines towards a protec- 

 tive mimicry of this queerly fortunate genus. 



The pulmonates unite both sexes in one individ- 

 ual, but it requires the mutual union of two indi- 

 viduals to fertilize the eggs. The eggs are laid in 

 May or June, when large numbers of snails gather 

 in sunny places. When about to lay, the snail 

 burrows into damp soil or decaying leaves, under- 

 neath a log, or in some other spot sheltered from 

 the sun's rays, and there drops a cluster of thirty 

 to fifty eggs looking like homoeopathic pills. Three 

 or four such deposits are made and abandoned. 

 This is the ordinary method of the genus Helix, 

 but some of the land and all the pond snails pre- 

 sent variations. The ova of slugs are often at- 

 tached by the ends in strings, like a rosary, and 

 many deposits are made during the year. Buli- 

 mus and other South American genera isolate each 

 egg, which in the case of some of the largest spe- 

 cies is as big as a pigeon's. Vitrina and Succinea 

 glue them in masses upon stones and the stems of 

 I)lants, while the tropical hulimi cement the leaves 

 of trees together to form nests for their progeny. 



296 



