Diseases of the Reproductive Organs 267 



struggle is kept up long enough the bird will become ex- 

 hausted, and show it by keeping quiet, with roughened 

 plumage and the general aspect of being ill. Sometimes the 

 egg can be felt from the vent. 



All these general symptoms of egg bound condition may 

 be observed m mild form in a great many cases with birds 

 which subsequently lay the egg without trouble. In many 

 instances the extrusion of an egg which is finally successfully 

 laid is attended with a good deal of difficulty. There are 

 all degrees of gradation between this somewhat difficult 

 but still normal laying and the condition of complete obstruc- 

 tion of the oviduct where the egg cannot be passed at all. 

 The practical consideration to which this leads is that one 

 should not be too hasty in applying treatment for the egg- 

 bound condition. A diagnosis of the trouble, in other words, 

 should not be finally settled upon until there remains no 

 doubt that the hen is not going to pass the egg without help 

 from the outside. 



It must also be remembered that in many cases of obstruc- 

 tion of the oviduct, the obstruction is so far up that it cannot 

 be felt from the outside. In such cases the diagnosis must 

 be made upon the general behavior of the hen, and in partic- 

 ular in regard to going frequently on the nest without 

 laying. 



Etiology. — In considering the causes of obstruction of 

 the oviduct it is necessary to distinguish between several 

 different sorts or categories. This may be done as follows : 



1. Simple "egg bound" condition, in which a normal egg 

 is lodged in the uterus or vagina and cannot be expelled. 

 This inability to expel the egg may be due to any one or a 

 combination of the following causes acting together : 



a. Egg of too large size, so that it is mechanically difficult 

 or impossible to force it through the natural passage. Robin- 

 son regards this as the most common cause. 



