414 RAYMOND PEARL AND M. R, CURTIS 



amount of mixed albumen and yolk was surrounded by peri- 

 toneum by which it was firmly attached to the abdominal fat 

 and the right side of the colon at the posterior end of the body 

 cavity. (2) A partly collapsed soft shelled egg, surrounded 

 by peritoneum which attached it to the peritoneum covering 

 the left kidney, lay between the left kidney and the oviduct 

 just behind the ovary. (3) A soft shelled egg, surrounded by 

 a very thin sheet of peritoneum, was attached to the right side 

 of the intestinal mesentery just opposite the ovary. (4) A 

 normal hard shelled egg occupied the posterior end of the body 

 cavity to the left of the intestine. A part of the shell was cov- 

 ered with peritoneum. (5) A soft shelled egg not surrounded 

 by peritoneimi lay just behind 3, into the side of which it was 

 indented. (6) Two yolkless membrane shelled eggs were free in 

 the body cavity among the convolutions of the oviduct. 



This bird was clearly discharging eggs into the body cavity 

 at a rapid rate. These eggs were evidently moved about in 

 the body cavity by the movements of the intestine and ovi- 

 duct until they were pushed into some portion of the cavity 

 where they remained quiet long enough for the local peritoneal 

 surface to throw out a surrounding envelope of peritoneum. 

 The four eggs attached or in the process of being attached were 

 at the four corners of the abdominal cavity and were therefore 

 in positions least likely to be affected by the movements of 

 digestion and egg formation. 



It sometimes happens that yolks become attached to the 

 peritoneum forming the intestinal mesentery or the oviduct lig- 

 aments. Apparently if an egg or a yolk free in the body cavity 

 is allowed to remain quietly in one position the adjacent peri- 

 toneum throws an enclosing membrane around it. If, on the 

 other hand, it is kept in motion especially if it becomes broken 

 and spread out over the general peritoneal surface it is not 

 enclosed by peritoneum but is absorbed directly. 



Whether the eggs are absorbed directly or after they are 

 enclosed by peritoneum must depend partly on the rapidity 

 with which they enter the body cavity, partly upon the strength 



