540 PHYSIOLOGY AT THE FABM. 



tion in the blood during pregnancy implies the simultaneous 

 accession of sulphur and phosphorus in corresponding propor- 

 tion. Though it is by no means a perfectly settled point in 

 physiology, we may in the mean time take it for granted that 

 a larger amount of food affording fibrine, and, by consequence, 

 sulphur and phosphorus, is required by the breeding-mare than 

 by the same mare when merely employed in ordinary farm or 

 other work. The distinction between vegetable fibrine and 

 vegetable albumen cannot always be drawn in the analysis of 

 the grasses and other articles of food fit for the farm quad- 

 rupeds. This distinction is, however, very manifest in the 

 seeds of the cerealia or corn-grasses : thus the gluten, as it is 

 termed, of wheat consists essentially of fibrine hence the 

 value of the advice as to giving corn to breeding-mares offered 

 in the quotation made above from Stonehenge. 



Fibrine, gelatine, and chondrine may be regarded as the 

 proximate principles most abundant in the embryo colt, as of 

 other embryos, during the period of its development. As 

 to fibrine, there is a sure resource in the grains of the cereal 

 grasses, but physiological chemistry is as yet far behind in re- 

 gard to the origin of gelatine and chondrine. Both are nitro- 

 genous proximate principles, and hence obviously must require 

 nitrogenous vegetable proximate principles to afford them. 

 There is, however, this difficulty in reasoning concerning them, 

 that neither gelatine nor chondrine exists in the blood of mam- 

 mals ; nor, as far as is yet known, is there any compound 

 in vegetable nature corresponding to either. But as gelatine 

 and chondrine, or compounds which represent them, are con- 

 tinually supplied by the blood of adult animals to their living 

 frame, it seems probable that the blood of the mother, when 

 duly recruited by the use of common nourishing food, is capa- 

 ble of affording these proximate principles to the embryo in 

 the requisite quantity. 



