146 BRITISH SERPENTS. 



mate. It is manifestly impossible to reconcile such 

 varying statements as these, unless one lumped them 

 all together and said that the adder family varies in 

 number from 5 to 40, which would be very apt to 

 convey the impression that very little was known 

 about it. An author can only give his own opinion 

 and the reasons for an^iving at it, which latter point is 

 too frequently omitted. People often say that they 

 once killed an adder which had its young ones play- 

 ing about it, the young numbering about such and 

 such a figure. These figures are of necessity a very 

 hasty estimate on the part of tlie observer, made, 

 moreover, at a very exciting moment. It is not an 

 easy matter to count a number of young adders 

 scuttling away and at the same time keep a careful 

 eye on the mother ; and very little reliance is to be 

 placed on this kind of haphazard evidence. There is 

 only one reliable method of observation applicable to 

 adders in a state of nature, and that is the dissection of 

 a sufficiently large series of gravid female adders shortly 

 before the time of parturition} This condition of the 

 female may be found, as has been said, in the month 

 of August. At this time the embryo adders are well 

 on in development, and can be handled and counted 

 with ease and accuracy. They are several inches long, 

 according to the stage of development, and every 

 embryo that is to be born can be taken out of the Qgg, 



^ This is also the method adopted to deteriuiue the relative pi^o- 

 portioii of the sexes. 



