OF COCHLITOMA ZEBRA IN CONFINEMENT. 381 



and eaten lettuce on February 8th, and then retired again. 

 Only two survived the winter. 



November 25th. — The two adult var. obesa, as well as the 

 young ones, commenced to hibernate, and they remained more or 

 less, but not continuously, inactive till February 8th, 1915. 



May 24th, 1915. — The smaller adult var. obesa buried itself, 

 and as it did not rise again I dug it up on July 12th, when I 

 found it was dead, after being from fourteen to sixteen months 

 in confinement. 



Winter, 1915-16: October 9th. — The two young var. fulgurata 

 hibernated. One came up January 6th, the other on the 29th. 



November. — During this month the single adult and the young 

 var. obesa buried themselves till January. The former rose on 

 the 20th and remained on the surface till March 2nd, when it 

 died, after about two years in confinement. 



Winter, 1916-17. — Two young wax. fulgurata began hibernat- 

 ing in September, but roused up and ate at the end of February ; 

 the weather, however, becoming very cold caused them to go 

 below again till late in March. One died in June, when about 

 three years old. 



November. — There were now only six young var. obesa living, 

 these began to hibernate during this month. They did not, 

 however, remain continuously below, but came up at different 

 times, though they did not eat. Three died in February and 

 two in March, thus only one specimen remained which belonged 

 to the first brood. 



Winter, 1917-18. — The solitary specimen of var. fulgurata 

 began hibernating at the end of September and roused up at the 

 end of January. The single example of var. obesa was only 

 dormant from December 15th to January 24th. 



Winter, 1918-19. — Var. fulgurata hibernated from the first 

 week in September till February 22nd. Var. obesa from the 

 first week in October till February 21st. 



Winter, 1919-20. — Var. fulgurata hibernated from September 

 29th till February, when it came up, but retired again below till 

 the middle of March. Var. obesa was buried from October 6th 

 till the middle of March. 



The hibernation of the original var. fulgurata during our 

 summer may be explained by the fact of that season being dry 

 and cooler in the district whence it came, when it would naturally 

 rest. There being no marked difference between the dry and 

 wet seasons at Port Elizabeth would cause var. obesa to be more 

 adaptable. It must be remarked, however, that the young var. 

 fulgurata did not follow the example of their parent, but that of 

 var. obesa. 



The conservatory in which the molluscs lived was heated, and 

 did not fall below 45° F. at night in winter. Nevertheless, they 

 seemed to feel variations in temperature, for there was greater 

 mortality in cold weather, and if they roused up earlier from 

 hibernation during a mild spell they generally went down again 



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