78 Diseases of Poiiltn/ 



Peritonitis probably always follows the entrance of fecal 

 matter into the body cavity through perforation of the 

 intestines. Perforations may be caused by severe inflamma- 

 tion of the intestinal walls, or by the puncturing of the wall 

 by parasitic round worms or other parasites, or by sharp 

 pointed foreign bodies pushing through. Birds have a 

 pernicious habit of picking up bright pieces of metal, glass, 

 etc. Cases of peritonitis have occurred in the Maine Agri- 

 cultural Experiment Station flock which were caused by 

 the entrance of partly digested food from the gizzard through 

 a perforation caused by a small nail, a watch spring or a pin. 



By far the largest number of cases of peritonitis which 

 have occurred in the Maine Station flock, however, have 

 been associated with the failure of yolks to enter the oviduct 

 or with the backing of partly formed eggs into the body cavity. 

 Somewhat extensive studies ^ have shown that even when 

 it is impossible for yolks to enter the oviduct the reproduc- 

 tive organs pass through their normal active cycles. The 

 yolks are ovulated into the body cavity. Further if yolks 

 can enter the oviduct, but if their passage is prevented at 

 some level of the duct, either the partly formed egg remains 

 in the duct forming immense masses (concrements) or they 

 are carried back into the body cavity by antiperistalsis. 

 These studies have shown that in about three-fourths of the 

 experimental cases the birds are able to absorb these yolks 



1 Pearl, R., and Curtis, M. R., "Studies on the Physiology of 

 Reproduction in the Domestic Fowl," VIII. On some Physiolog- 

 ical Effects of Ligation, Section or Removal of the Oviduct. Jour. 

 Expt. Zool, Vol. 17, pp. 395-424, 1914. 



"Studies on the Physiology of Reproduction in the Domes- 

 tic Fowl," X. Further Data on Somatic and Genetic SteriHty. 

 Jour. Exp. Zool, 1915. 



Curtis, M. R., "Studies on the Physiology of Reproduction in the 

 Domestic Fowl." XII. On an AbnormaHty of the Oviduct and 

 its Effect upon Reproduction. Biol. Bui., Vol. XXVIII, pp. 154- 

 16.3, 1915. 



