421 



Valenciennes's three specimens should have all been of normal size. 

 There probably was some abnormal factor which brought about this 

 result and was not at all taken account of. He says nothing whatever 

 regarding the breed of the birds which produced these eggs. It is possible 

 that they were from bantams, in which case they might well have been 

 of the size normal for larger breeds. The measurements given by Akers 

 (loc. cit.) show his specimen to have been, like the present, of abnormally 

 large size. Unfortunately he gives peripheral rather than diametral 

 figures, stating that this specimen was "6 V2" around" one way and 81/2" 

 the other. Its weight was 41/2 oz. Transferring to metric figures and 

 where possible to a diameter we get: 



Akers' specimen: Breadth = 52,6 mm 

 Weight = 127,6 g. 



These values show that Akers' egg was distinctly larger than the 

 present specimen. 



A question of some interest is as to how this triple-yolked egg 

 compares in size with double-yolked Plymouth Eock eggs. The following- 

 data are averages obtained from the measurement of 18 double-yolked 

 eggs in the collection belonging to this laboratory. 



Double yolked eggs : Mean length = 68,6 mm 



- breadth =46,8 - 



- weight = 86,26 g. 



It is evident from these figures that the triple-yolked egg is of 

 approximately the same size as the average double-yolked egg from 

 Barred Plymouth Eock hens. The size of eggs is evidently not simply 

 proportional to the number of yolks Avhich they contain. 



The question of what is the exact relation existing between the 

 bulk or weight of eggs and the number of yolks which they contain is 

 of sufficient interest to warrant special consideration. The following 

 classes of hen's eggs are known to occur: a) yolkless eggs. These are 

 the small so-called "cock-eggs" or "witch-eggs" (Hexeneier, Windeier) ^, 

 which everyone who has kept poultry is familiar with. They never 

 contain a normal yolk. Occasionally they contain a small amount of 

 fluid yolk without any distinct yolk membrane. More usually these eggs 

 are without any trace of yolk, consisting merely of albumen, shell mem- 

 branes and shell, with a minute particle (hardened albumen, blood clot, 

 etc.) in the center, which serves as the nucleus around which the albumen 



G The folk-lore of these eggs forms an extremely interesting subject in itself. 

 The writer hopes to be able at some future time to put together for publication his 

 notes on the subject. 



