UNIVALVE MOLLUSCANS. 285 



each individual possessing the organs of both 

 sexes, they are not so as to sexual union ; repro- 

 duction can only take place when different indi- 

 viduals impregnate each other ; this union takes 

 place at the beginning of the spring, sooner or 

 later, according to the heat of the season. Their 

 courtship is singular, and realises the Pagan 

 fable of Cupid's arrows, for, previous to their 

 union, each snail throws a winged dart or arrow 

 at its partner. About twenty days after coupling 

 the snails lay, at different times, a great number 

 of white eggs, varying at each laying from 

 twenty-five to eighty, as large as little peas, 

 enveloped in a membranous shell, which cracks 

 wiien dried. They lay these eggs in shady and 

 moist places, in hollows which they excavate 

 with their foot, and afterwards cover with the 

 same organ. These eggs hatch, sooner or later, 

 according to the temperature, producing little 

 snails exactly resembling their parent, but so 

 delicate that a sun-stroke destroys them, and 

 animals feed upon them ; so that few, compara- 

 tively speaking, reach the end of the first year, 

 when they are sufficiently defended by the hard- 

 ness of their shell. The animal, at its first ex- 

 clusion, lives solely on the pellicle of the egg 

 from which it was produced. Providence, which 

 in oviparous and other animals, has provided for 

 the first nutriment of the young in different 

 ways, appropriating the milk of the mother to 



