536 PHYSIOLOGY AT THE FARM. 



must be sufficient, not only to nicaintain her blood in a state 

 adequate to supply the ordinary wants of her own system, 

 but also to bear the additional drain put upon it for the 

 development of the various textures entering into the structural 

 composition of the offspring which she carries in her womb. 



To determine theoretically what addition should be made to 

 the ordinary food of the mother, in order to enable her to 

 bring the work of reproduction to a perfectly successful termi- 

 nation, it would be necessary to institute a comparison between 

 the quantity and kind of material required for the repair 

 of the periodical loss in the substance of the mother's body, 

 under the amount of work obtained from her, with the quantity 

 and kind of material adequate at each particular stage of preg- 

 nancy, to produce the development of the foetus in the like 

 periods. It cannot be assumed in theory that a mere increase 

 of the ordinary kind of food will suffice to supply all that 

 the foetal foal requires for its perfect development ; for that 

 assumption would imply that the textures in the mother which 

 are undergoing waste by labour must, throughout pregnancy, 

 be the same, or of the same composition, as those which are, 

 at the same period, acquiring development in her offspring 

 within the womb. 



Physiological chemistry has not yet reduced to an exact 

 measure, fit to be expressed in figures, the precise additions to 

 be made to the food of such an animal as the mare during the 

 successive stages of her pregnancy, in order to insure the per- 

 fect development of the foal. Nevertheless, there are some 

 considerations that may not be without their use towards the 

 attainment of this object. 



The preliminary remark is, however, necessary, that a strict 

 attention to the food of breeding-mares should not supersede 

 a regard to the other circumstances that are conceived to exert 

 an influence in the production of what is called a hit, or signal 



