296 MAINE AGRICULTURAL EXPERIMENT STATION. 1916. 



By means of the data given in Table 2 it is possible to com- 

 pare the size, shape and degree of variability of the several 

 groups of dwarf eggs both among themselves and with normal 

 eggs. 



A. SIZE RELATION OF DWARF AND NORMAL EGGS. 



1. All classes of dwarf eggs are lighter in weight and both 

 shorter and narrower than normal eggs. This fact is of course 

 obvious from the most casual inspection of dwarf and normal 

 eggs. 



2. The cylindrical eggs studied were much lighter in weight, 

 decidedly narrower, but slightly longer than the eggs of the 

 prolate spheroidal type. 



3. Small yolked dwarf eggs are significantly smaller than 

 normal eggs and larger than the other classes of dwarf eggs. 

 That is the small yolked eggs are nearer the size of normal 

 eggs than are dwarf eggs with little or no yolk. 



4. The average length, breadth and weight are all slightly 

 higher for dwarf eggs which contain some free yolk than for 

 yolkless dwarf eggs. These slight differences are not certainly 

 significant. 



These results confirm the evidence from a study of normal 9 

 and multiple yolked 7 eggs that the amount of yolk (or other 

 nucleus) present in the oviduct is an important factor in deter- 

 mining the amount of albumen secreted in a given case. 



B. THE RELATIVE SHAPE OF DWARF AND NORMAL EGGS. 



Table 2 also gives data for a study of the comparative shape 

 of the several classes of dwarf and of normal eggs. It has 

 already been noted that there are two distinct shape groups of 

 dwarf eggs, cylindrical and prolate spheroidal eggs. The 

 cause for the distinctly different form cannot be certainly 

 decided from the material at hand. In several cases of cy- 



"Curtis, M. R. 1914, a. Studies on the Physiology of Reproduction 

 in the Domestic Fowl. VI. Double and Triple-Yolked Eggs. Biol. Bui. 

 Vol. 26, pp. 55-83. 



T Pearl, R. 1910. A Triple-Yolked Egg. Zool. Anz., Bd. 35, pp. 417- 

 423- 



