PHYSIOLOGICAL 123 



to come in use in the winter months and so produce calves and 

 subsequently lactate at a season when under present conditions 

 parturition is infrequent. It must be remembered, however, 

 that the heat periods of the late autumn are sometimes very 

 transient and hard to recognize in cattle, that it is often only by 

 close and constant observation and trial that it can be discovered 

 that a cow or heifer is in a condition to take the bull, and conse- 

 quently a "cowman" may let a "period" pass, and perhaps 

 lose the chance of getting the cow in calf for that season, through 

 failing to detect any vaginal discharge or other sign of oestrus. 



In this chapter reference has been confined to certain problems 

 in "agricultural physiology" of which the writer has had direct 

 cognisance or practical experience. In the preface to this book 

 attention has been directed to the need for investigation upon 

 heredity and the way in which this can best be done with the 

 view r of obtaining practical results. The other branches of 

 animal physiology contain fields of inquiry of equal importance, 

 both for the agriculturist and for the man of pure science, and 

 innumerable instances might be given. But enough has been 

 said to indicate the nature of the work, the high interest which 

 the subject possesses, and the need for applying scientific 

 method to the live-stock industry, not only for the benefit of 

 those directly concerned with it, but on behalf of the nation as 

 a whole. 



