312 SCIENTIFIC FEEDING OF ANIMALS 



by measurement of the ducts that the whole of 

 these, together with the cavities of the udder, have 

 a capacity not greater than six pints of milk, 

 whereas at a milking often more than twice this 

 quantity is got. According to this a portion of 

 the milk must certainly only leave the cells of the 

 alveoli during milking. 



Be that, however, as it may, the fact remains 

 that the time between successive milkings has a con- 

 siderable influence upon the milk formation. In 

 an experiment where the cows were milked after 

 different lengths of time, it was found that the milk 

 obtained per minute was as follows : — 



With intervals of 12 hours 5-29 g. milk per min. 



The shorter, then, the interval between the times 

 of milking, so much greater, up to a certain point, 

 was the quantity of milk obtained. Where milking 

 was performed each hour the yield fell suddenly, 

 from which it may be assumed that the otherwise 

 favourable stimulus gave rise to pain if repeated 

 too frequently. In general the extra amount of 

 milk which can be got by frequent milkings is very 

 much overestimated, for although considerable 



