648 THE DISEASES AND DISORDERS OF THE OX. 



restless, often lies down, strains, rises again, changes her 

 position, looks to her flanks, and carries the tail higher than is 

 usual. 



During the earliest periods of gestation it is very difficult to 

 decide if an animal is pregnant. In cases when the hand can 

 he passed up the rectum, the presence of the fcetus can be 

 detected in the form of a small, roundish, and slightly mov- 

 able body situated below and without the intestine. If the 

 hand be quietly kept in this situation, and pressed upon the 

 enlargement, voluntary movements in the living embryo will 

 now and again be recognised. Some persons prefer to introduce 

 the hand into the vagina, and carry it towards the os uteri so as 

 to ascertain its condition, for the mouth of the womb is closely 

 shut during gestation, and at this time it contains a layer of 

 thick albuminous matter. However, such manipulations are 

 liable to lead to abortion, and hence should not be resorted to. 

 Percussion over the uterus is also of great assistance in regard 

 to diagnosis, and some persons speak of auscultation most 

 favourably, maintaining that the sound of the foetal heart can 

 often be detected. 



The percussion should be carried out on the right side, the 

 rumen being situated in the left division of the abdomen. If 

 the period of gestation be advanced, foetal movements can be 

 seen while we stand by the side of an animal. In the case of 

 the mare, the custom is not unfrequently practised of giving 

 cold water to drink for the purpose of making the foetal move- 

 ments stronger and quicker. However, this is a very repre- 

 hensible practice, since spasms and even death may be induced 

 by it. 



As a rule the mare carries her young for nearly forty-eight 

 weeks, the cow forty, the ewe twenty-two, the bitch nine, and 

 the sow sixteen. According to Earl Spencer, the probable 

 period of gestation of a cow should be considered to be 284 or 

 285 days. 



Dr. Carpenter remarks that "the average length of time 

 which elapses between conception and parturition in the human 

 female appears to be 280 days or 40 weeks. We must attribute 

 the prolongation of the period to some peculiarity in the embryo, 

 derived from its male parent." 



Earl Spencer observes that ** from the cows whose period 



I 



