MISCELLANEOUS NOTES. 



1337 



No. XXIV.— COBRA BREEDING AT PAREL. 



During the past ten years many of the cobras (Naia tripudians) sent to 

 the Bombay Bacteriological Laboratory have laid eggs while in captivity, 

 but hitherto all attempts at hatching out young cobras have proved 

 failures. Whether left with the mother, or kept apart from her, the eggs 

 have always shrivelled iip and no development of embryos took place. 

 When kept in an incubator at blood-heat, the eggs became rotten in a few 

 days, and when buried in dry sand they shrivelled up. 



In 1905 a full grown krait {Bungarus cceruleus) and some half dozen eggs 

 were dug up close to the Laboratory. Some of these eggs were kept in a 

 box with the mother, and some were buried in the soil in which they were 

 found. Both sets of eggs remained infertile. 



In 1909, Major Liston, I. M.S., suggested that the cobra mother and her 

 eggs should be placed in a glass case half full of sand, that the case should be 

 darkened by winding cloth round it, and that the sand, and the cloth cover 

 of the case be kept moist. Next day one egg was examined and a trace 

 of embryo found. Unfortunately the mother died 9 days afterwards, and 

 the eggs shrivelled up. 



This year (1910) we had occasion to require a considerable number of 

 cobras for experimental purposes, and four out of 21 laid eggs, and gave 

 us the chance of experimenting further. Two of these cobras laid 21 and 

 22 eggs respectively, the other clutches were not counted as the eggs were 

 glued together and mixed up with shreds of the mother's cuticle, and it 

 was thought advisable to leave them alone. These latter batches all proved 

 failures as far as hatching out young ones was concerned. 



With regard to the period of the year when young cobras may be looked 

 for, our experience is that the month of May is the usual time. Thus from 

 1st January to Slst May 1910 we received 24 cobras, of which 4 laid eggs ; 

 while after the Slst May 25 more cobras were received and none laid eggs 



The following table shows the date of receipt of cobras, and the laying 

 of eggs :— 



Th& following is an account of the plan we employed with success in the 

 case of the eggs of cobra No. 28 : — 



The eggs were laid in the tin biscuit box in which the cobra was kept 

 on 12th May J 910. The eggs, 21 in number, were placed on the surface 



