i88 



MAYNIE R. CURTIS. 



the shell was 8 gm. The enclosed egg weighed 29.36 gm. At- 

 tached to one pole of the enclosed egg by the inner layer of 

 thick albumen was a white mass which on close examination 

 appeared to be a triangular piece of egg membrane. The en- 

 closed egg was membrane-covered. Its contents resembled a 

 large normal egg as it appears while it is in the upper part of 

 the albumen-secreting region of the oviduct. That is, it con- 

 sisted of a large yolk (weight 23.16 gm.) surrounded by a thin 

 layer of very thick clear albumen which adhered closely to the 

 yolk. This albumen weighed only 5.57 gm. The enclosed egg 

 was distinctly pointed and lay with its pointed end toward the 

 blunt end of the enclosing egg. It has been noted that in all 

 the cases described and reviewed by Parker (12) when a pointed 

 end was distinguishable in both included and including eggs the 

 pointed end of the former always lay toward the pointed end of 

 the latter. In this particular, therefore, the above described 

 case differs from those known to Parker. Since specimen No. 7 



FIG. 4. Diagram showing the structure of double egg No. 7. a = albumen; 

 m = egg membrane; s = shell; y = normal yolk. 



also shows the poles of the included egg in the reverse direction 

 to those of the including egg, this case will be described and 

 the reversal of axes will then be discussed. 



Specimen No. 7 was brought to this laboratory by Dr. W. J. 

 Morse. This egg was a large membrane-covered egg with a short 

 tubular attachment. A diagram showing its structure is given 



