22 



EXPEBIMENTS IN THE BREEDING OF CERIONS. 



In May 1916 Colony E resembled Colony A in development. The 

 mollusks were spreading over a wide area and many young and adult 

 shells were in evidence everywhere. The same conditions obtained in 

 1917, and in January 1919 we were able to state that this colony was 

 spreading and multiplying rapidly. Young and old could be seen 

 everywhere on the ground. Most of the old were partly burrowed in 

 the tilted position, feeding or ovipositing. The extreme young, as 

 usual, were mostly about the base of tussocks of grass. Half-grown 

 specimens were also plentiful on the moist ground and on the lower 

 portion of the bushes and grass. 



