264 The Field Naturalist' s Quarterly Nov. 



by anatomists the oviduct, which leads from the neighbour- 

 hood of the ovary to the posterior opening. In this tube 

 fertilisation takes place, and the further stages of develop- 

 ment occur. There are of course two ovaries, a right and a 

 left ; and two oviducts corresponding to them. It frequently 

 happens in the adder that developing eggs are found in only 

 one oviduct ; in my own experience I have found that when 

 this is the case it is the right more often than the left which 

 contains the eggs. In the above reports, where the " ovary " 

 must be taken to mean the oviduct, it is not stated on which 

 side of the body the eggs were found. While in the ovi- 

 duct, the developing embryo becomes surrounded by a large 

 quantity of yolk, on which material it depends for its growth. 

 This amount gradually diminishes as the young adder gets 

 nearer its time of birth, until at full time there is none left. 

 If any large quantity of food-material is found in a develop- 

 ing egg, it is a sure sign that full time has not been reached. 

 In this respect the eggs of the adder resemble those of birds ; 

 but in birds, in addition to the yolk, there is outside that a 

 covering of albumen which serves as a buffer protecting the 

 embryo from injury by movement of the egg. This is not 

 found in adders' eggs. I hope my correspondents will be 

 able to understand the above, which is as clear as I can 

 make it without the use of technical terms. Their difficulty 

 arose from the inaccurate use of the word "ovary." 



On the final paragraph of Mr Tegetmeier's letter I do not 

 propose to dwell. The statements contained therein are so 

 sweeping that they lose the weight they might otherwise 

 have. Any one who has dissected the gullet of an adder 

 and found therein a field-mouse, or a water-vole, or other 

 articles of diet, can see at once that there is no anatomical 

 impossibility in the alleged occurrence, and of course when 

 the entrance to the gullet is distended for the passage of any 

 material, air must follow. Further, to kill an adder by try- 

 ing to cut off its air-supply takes a very long time, much 

 longer than one would suppose the adder-mother to retain 

 her young if she did thus dispose of them. So it is that one 

 finds frogs can survive in the gullet of the harmless ring- 

 snake for, in some instances, twenty minutes, and be none 

 the worse for their temporary incarceration. 



