210 MILK. 



their structure with that of the skin. This is an im- 

 portant observation, as indicating the simplicity of 

 method by wiiich the purposes of nature are accom- 

 plished ; and as a corollary to this simplicity, the 

 effect of any agency, whether external or otherwise, 

 on an animal, cannot be limited in its effect to one 

 part only, but its influences must be more or less 

 general in their nature. 



We are now prepared to examine more particularly 

 into tlie structure and reactions of milk, as we have 

 seen that, through its method of formation, these 

 must be influenced largely by the structure of the 

 animal from which it is obtained. 



Milk is one of the animal fluids which contains a 

 morphological element, which in the form of myriads 

 of minute globules of mixed fats, enclosed each in an 

 enveloping substance, floats at will in a fluid com- 

 posed of sugar of milk, caseine, etc., in solution. 

 In this paper we shall consider only this globule, 

 from which the milk derives its color and capacity, 

 and which has sufficiency of form and chai-acter to be 

 influenced by variation in breed and environment, 

 and to influence itself in turn the character of those 

 important dairy products, butter and cheese. 



These globules are of varying size, some so small 

 as to appear as granules under a magnifying power 

 of 800 diameters, others occasionally attaining a size 

 of 1-1500 of an inch. The small globules, for an 

 increased power has invariably defined them as such, 

 I shall for convenience term granules. As 1-27000 

 inch is, with my micrometer, a convenient division, 



