292 MAINE AGRICULTURAL EXPERIMENT STATION. I916. 



by a nine months old pullet for comparison. From this photo- 

 graph it may be seen that there are two distinct types of 

 dwarf eggs in respect to their shape. The prolate-spheroidal 

 type similar in shape to a normal egg and the cylindrical type 

 which is much longer in proportion to the breadth. The 

 cylindrical eggs are shown in the first column of Fig. 1. These 

 cylindrical eggs occur much less frequently than do the dwarf 

 eggs of the prolate spheroidal type. 



Not only do the dwarf eggs differ in respect to size and 

 shape, but there is a difference in internal structure. Some of 

 these eggs contain no yolk but appear to be formed around a 

 nucleus which consists of a few strings of coagulated albumen, 

 apparently untwisted chalazal threads, and there are also some- 

 times small lumps of hardened albumen or small blood clots 

 associated with these chalazal threads. Some dwarf eggs contain 

 small yolks in yolk membranes. More than half of all the 

 eggs opened, however, contained some yolk which was not 

 enclosed in a yolk membrane. Dwarf eggs may then be classi- 

 fied according to the non-occurrence of yolk and the condition 

 of the yolk when present as, first, yolkless, second, with some 

 yolk not in a membrane and, third with one small yolk. In 

 Table I the dwarf eggs are classified both according to form 

 and yolk content. 



Table i . 



Showing the Classification of Dwarf Eggs both as to Shape 

 and as to Yolk Content. 









Number 



Per cent. 















with 



with 



Number 



Per cent. 







Number 



Per cent. 



some 



some 



with 



with 



Total. 



Shape. 



yolkless. 



yolkless. 



yolk 

 not in a 

 mem- 

 brane. 



yolk. 



one 

 small 

 yolk. 



one 

 small 

 yolk. 





Shape not known 2 . . 



5 



38.46 



8 



61.54 











13 



Prolate spheroidal 

















shape 



83 



33.33 



139 



55.82 



27 



10.84 



249 



Cylindrical shape. . . 



8 



66.67 



4 



33.33 











12 



Total 



96 



35.03 



151 



55.11 



27 



9.85 



274 







2 Dimensions not recorded. 



From the last line of Table 1 it is seen that 96, or 35.03 

 per cent, of the dwarf eggs opened were yolkless. The other 



