172 Veterinayy Obstetrics 



latter term, we recognize a true or erethetic nyniphomania and 

 the so-called dumb estrum (stillochsigkeit), in which latter, re- 

 gardless of the existence of the sinking of the great sciatic liga- 

 ments, symptoms of estrum are either entirely wanting or are 

 only of a very feeble cliaracter. 



A. Nymphomania. 



General Symptoms. 



Under normal conditions in non-pregnant cows, estrum occurs 

 ev-ery three weeks and, if the milk secretion is not too intense, it 

 begins from 6-8 weeka post part ufn. Vascillations of the estrual 

 periods between 21-28 days must still be regarded as normal, 

 while less than 21 or more than 28 days, as for example, estrual 

 periods of 6-9 weeks, according to our statistical observations ex- 

 tending over several years, can no longer be viewed as normal 

 because experience teaches that animals with reduced or pro- 

 longed estrual periods either fail to conceive, or do so only with 

 difficult}'. On the whole, we have observed that the normal 

 duration of estrum in the cow is 15-24 hours and that its pro- 

 longation to 30-;,6-48 hours, progressively diminishes the proba- 

 bility of conception. 



The probability of conception is also decreased if the duration 

 of estrum is very brief or if it is excessively intense or goes to 

 the opposite extreme and is very weak, as well as when there is 

 a marked or abundant sanguineo-mucous vaginal discharge after 

 the cessation of estrum. Only in exceptional cases have we ob- 

 served conception to occur at the first service in well nourished 

 cows, which, at times, remain in vigorous heat for fully 48 hours. 



All the varied deviations from the above described normal 

 estrum fall within the designation of " bulling " or of "dumb 

 estrum" and especially do we designate as nymphomania those 

 cases in which the estrum is excessive and irregular or is of too 

 permanent a character. 



In reference to the relation ])etween estrum appearing at the 

 normal period, the anatomical character of the ovaries and the 

 sinking of the broad ligaments of the pelvis, we may relate the 

 following details in cases presenting the common characteristic 

 that they fail to conceive. 



Quite exceptionally we met with cystic degeneration of the 



