EXPERIMENTS IN THE BREEDING OF CERIONS. 



15 



Our visit in 1913 showed that our Cerions had spread over all the 

 above-described territory. 



On April 21, 1914, we again visited this plantation and found 55 

 young of the first generation of Florida-grown individuals, 3 of which 

 had attained adult size; these we figured in the 1915 report, plate in, 

 figures 1 to 3, bottom row. They are discussed in the text. We trans- 

 planted these to a grassy spot about 62 feet northeast of the old 

 plantation on the same key. 



From this colony 76 adult shells of the first generation of Florida- 

 grown specimens were gathered in June 1915, measured, and photo- 

 graphed. The measurements are given in table 2 and the photographs 

 on plates 10 and 11. 



TABLE No. 2. Measurements of the first generation of Florida-grown Cerion viaregis 



from the second key north of Sands Key. 



On May 16, 1916, the old planting was doing well. Old and young 

 were up in the vegetation. The old colony occupied almost the same 

 extent of territory that it held the year before. The two other plantings 

 were all doing well. 



The planting was not visited in 1917 or 1918. In January 1919, 

 we again examined it and found the first planting flourishing. In 

 the new plantings, however, we did not find the mollusks abundant, 



