1038 Journal of Agricultural Research vol. vi.No. 25 



(5) Dwarf eggs may also be classified according to the absence of 

 yolk or its presence either as a small yolk in a yolk membrane or as 

 free yolk. 



(6) Of the 274 dwarf eggs opened 35.03 per cent were yolkless and 

 64.96 per cent, or nearly two-thirds, contained yolk. The yolk was in- 

 closed in membrane in only 9.85 per cent of the dwarf eggs opened, while 

 free yolk was present in 55.11 per cent of these eggs. 



(7) Dwarf eggs with small yolks, while distinctly smaller than normal 

 eggs, are significantly larger than dwarf eggs with little or no yolk. 



(8) A comparison of the relative size of the several groups of dwarf 

 eggs, normal eggs, double-yolked and triple-yolked eggs furnish a con- 

 tinuous line of evidence that the amount of albumen secreted depends to 

 a large extent at least upon the degree of immediate stimulation due to 

 the amount of yolk present. 



(9) Although the evidence available is not sufficient for a positive 

 statement, the shape of the cylindrical egg is probably due to the long 

 form of the stimulating nucleus. 



(10) Dwarf eggs with small yolks have indices which are higher than 

 those for normal eggs and lower than those for other prolate-spheroidal 

 dwarf eggs. This difference in index in the three groups is the reverse of 

 their difference in size. 



(11) This negative correlation between the shape, index, and size 

 extends the evidence from former researches that the smaller the egg the 

 broader it is in proportion to its length. 



(12) Two factors may be involved in producing this negative correla- 

 tion between shape index and size : First, the area of the glandular mucosa 

 under stimulation at any one time must be related to the size, particularly 

 the length, of the stimulating nucleus (yolk drop, normal yolk, or two or 

 three yolks in tandem). Second, the oviduct, which is a tube with elastic 

 walls, will offer more resistance to the passage of a large than a small body, 

 and therefore when the plastic egg is forced through it by peristalsis it 

 will exert a greater elongating pressure upon a large than a small egg. 



(13) Dwarf eggs of each class are exceedingly variable when compared 

 to normal eggs. This greater variation occurs in all the physical charac- 

 ters measured — that is, length, breadth, shape index, egg weight, yolk 

 weight, shell weight, and possibly albumen weight. 



(14) Dwarf eggs with small yolk resemble normal eggs in degree of 

 variability as well as in size and shape more nearly than do other classes 

 of dwarf eggs. 



(15) The several size characters show different degrees of variation. 

 They may be arranged from most to least variable as follows : Egg weight, 

 length, and breadth. This arrangement is the same for dwarf and 

 normal eggs. 



