BULLETIN 255. 



DWARF EGGS OF THE DOMESTIC FOWL. 1 

 By Raymond Pearl and Maynie R. Curtis. 



In any breed of domestic fowls there are occasional indi- 

 viduals which produce one or more small eggs which are from 

 one-tenth to one-half the size of normal eggs. Various super- 

 stitions have been associated with these small eggs and in 

 many parts of the world the eggs are still called by names 

 derived from the superstitions formerly common to the region. 

 A common superstition which persisted nearly to our own time 

 was that old cocks produced these eggs. Hence they are still 

 often called "cock eggs." At an early period it was believed 

 that if a cock egg was incubated it would hatch into a serpent, 

 the basalisk, whose breath or look was fatal. Other less 

 definite superstitions considered these eggs as good or bad 

 omens. In some places they were used as charms to bring 

 misfortune to one's enemies and were called "witch eggs." 

 In other places they were called "luck eggs" for it was believed 

 that if one was thrown over a building any wish made by the 

 thrower while the egg was in the air was sure to come true. 

 Since no one of these names is generally accepted we have 

 decided to use the modern descriptive term "dwarf eggs." 



The dwarf egg is more common than any other type of 

 abnormal egg except the double-yolked egg. It has emerged 

 from the age of superstition with the cause for its production 

 inadequately explained. It is the purpose of the present paper 

 to discuss (i) the different types of dwarf eggs in respect to 

 shape and also in respect to contents; (2) the variability in 

 respect to size and shape; (3) the interrelations of the varia- 



bilis bulletin is an abstract of a more detailed paper by the same 

 authors published under the title "Studies on the Physiology of Repro- 

 duction in the Domestic Fowl. XV. Dwarf Eggs." Journal of Agricul- 

 tural Research, Vol. VI, pp. 977-1042, 1916. 



