14 BOARD OF AGRICULTURE. 



about in it freely, and whiten every part with their presence. 

 In form, they are all round or egg-shaped, but in size they 

 are very unequal, varying all the way from one two-thousandth 

 of an inch in diameter down to indistinguishable minuteness. 

 Just how milk is formed from the blood is not clearly knoAvn, 

 that I am aware of; but that it undergoes changes in the 

 capillaries and minute ducts, through which it passes to the 

 larger milk-tubes, I consider probable. In fact, milk changes 

 all the way from its introduction into or formation in the 

 udder, till it passes out of the teat. 



The system of branching tubes, which permeates all parts 

 of the lacteal glands and conveys the milk to the teats, per- 

 forms functions analogous to those performed by the stomach, 

 — doing double duty in the way of excreting juices to mingle 

 with and modify their contents, and, at the same time, absorb- 

 ing a portion of these contents as they pass along through 

 them. And they also perform another function in common 

 with the stomach ; to wit, they develop in their excretions a 

 ferment, which mingles with the milk, and produces a distinct 

 species of fermentation in the milk as it passes, just as the 

 ferment developed in the juices of the stomach produce fer- 

 mentative action in the contents of that organ. I arrive at 

 this conclusion partly by observed facts, and partly from the 

 analogous functions of the stomach and other organs. 



A word in regard to fermentation. In all those cases where 

 a small amount of matter quickly communicates to a large 

 amount of matter its own peculiar conditions, as when a little 

 leaven is added to a large lump of dough, a little taint to 

 animal matter, or a little yeast to a large amount of beer, the 

 changes which occur in the larger mass of matter are accom- 

 panied with the development of myriads of living organic 

 germs, to whose growth and wonderfully rapid multiplication 

 the new conditions are ascribed. This fact of the presence 

 and growth of microscopic germs in a great number of cases 

 which have been examined, it is believed, warrants the conclu- 

 sion that in all similar cases of infection, where the new con- 

 ditions can be indefinitely communicated from one parcel of 

 matter to another, the active agent concerned in such changes 

 consists of minute germs, either animal or vegetable. When- 

 ever fermeutation occurs, it implies that the growth and mul- 



