988 Journal of Agricultural Research vol. vi.No. 25 



correlation between the weight of the yolk and the weight of the albu- 

 men — that is, the amount of albumen secreted is in part at least depend- 

 ent on the amount of immediate stimulation due to the quantity of yolk 

 in the duct. 



The results recorded for the different classes of dwarf eggs carry these 

 results further. The eggs which contain small-formed yolks are smaller 

 than normal eggs and larger than eggs which contain either little or no 

 yolk. That eggs with a small amount of free yolk are not certainly 

 significantly larger than eggs without yolk is explained by the fact that 

 the two groups were separated strictly on a basis of the presence or 

 absence of yolk. Dwarf eggs which do not contain formed yolks contain 

 as nuclei lumps or drops of free yolk, lumps of hardened secretion, blood 

 clots, or fibers of coagulated albumen. The size of these nuclei vary con- 

 siderably. A single drop or a very small lump of yolk threw the egg into 

 the class of free-yolked dwarf eggs. Several yolkless dwarf eggs con- 

 tained nuclei larger than some of the lumps or drops of yolk found in the 

 free-yolked dwarf eggs. In a broad way at least the size of the egg 

 varies with the size of the nucleus — that is, a large dwarf egg contains a 

 considerable amount of yolk or some other large nucleus. A very small 

 one contains a small nucleus. Since the irregular particles can not be 

 accurately measured, the degree of this relationship ' can not be ascer- 

 tained. 



A comparison of the mean egg size of the several groups of dwarf eggs 

 classified according to yolk content confirms the evidence obtained 

 from a study of normal and multiple-yolked eggs that the amount of 

 yolk (or other nucleus) present in the oviduct is an important factor in 

 determining the amount of albumen secreted in a given case. 



b. — relative; shape of dwarf and normal eggs 



Tables IV and V also give 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: Cylin- 

 drical and prolate-spheroidal eggs. A comparison of the mean indices 

 shows that cylindrical dwarf eggs are longer in proportion to their 

 breadth than are normal eggs, while prolate-spheroidal eggs are pro- 

 portionately shorter than normal eggs. It is also seen that dwarf eggs 

 with small yolks are nearer the shape of normal eggs than are dwarf 

 eggs without formed yolks. 



The cause for the distinctly different form in cylindrical and prolate- 

 spheroidal dwarf eggs can not be certainly decided from the material at 

 hand. In several cases of cylindrical dwarf eggs the form of the nucleus 

 was not noted. However, in a few pronounced cases it was noted that 



1 On page 1000 it is shown that in dwarf eggs with formed yolks the yolk weight is highly correlated both 

 with the egg weight and the albumen weight. 



