12 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. XVIII. 



coriaceous, or cretaceous material. At a certain stage of embryonic 

 development in viviparous snakes, eggs in the sense just referred to 

 are to be found within the mother, invested with a leathery covering- 

 similar to that which is characteristic of the eggs in oviparous snakes. 

 In viviparous snakes, however, the egg undergoes a metamorphosis 

 never seen in the eggs of an ovipara. At a certain stage the leathery 

 investment disappears, and the embryo as it approaches full term is 

 found to be suspended in a limpid oily fluid, contained within a 

 delicate, transparent sac, which I take to be the amnion, a foetal not 

 a maternal structure. At this stage it appears to me to be exactly 

 comparable to the condition of a human infant born in caul. 



Even supposing that a snake discharges fertile ova, it by no means 

 follows that it is to be considered oviparous. Emotional and other 

 causes are known to operate upon many gravid animals so as to cause 

 in some ca^es the premature discharge of the fruits of generation, and 

 it is no unreasonable assumption to suppose that similar causes may 

 operate in the same direction in snakes. That they are susceptible to 

 nervous influences is certain, or how otherwise can one explain the 

 disagreeable habit so frequently evinced by captured snakes even 

 when quite unscathed, of disgorging the contents of their stomachs, 

 even when the rejectamenta are so far digested as to be unrecog- 

 nisable. 



Period of gestation. — From one of Colonel Bannerman's interesting- 

 domestic occurrences at Parel, it appears that the period from concep- 

 tion to discharge of the young exceeds six months. 



Breeding season. — From this last statement it appears that these 

 vipers are mating in the cold months. This receives confirmation by 

 a note of mine dated Cannanore 28th December 1903 : a male specimen 

 was brought me said to have been in copula; the female escaped 

 capture. In cold climates this implies that they, mate during the 

 season of hibernation. This, if true, appears most remarkable for at 

 this season a snake's vitalities are at their lowest ebb and not one 

 would think favorable to the consummation of so important a 

 function. 



Fecundity. — It is a prolific snake producing sometimes more than 60 

 young at a time. Some mothers, however, are more modest in their 

 estimate of matrimonial duty, contenting themselves with a family of 

 less than 20. One recorded by me in this Journal contained but one 



