308 GENERATIVE SYSTEM. 



tuation of the mammaB, are — that they are well protected, by the 

 trunk above and the thigh on either side, from external injury, 

 that they are conveniently placed for the foal, and that they do 

 not in the least interfere with progression. 



Volume. — In fillies and virgin mares the udders are so small 

 that there hardly appears to be any ; and in mares who have not 

 hud more than one or two foals, they likewise regain nearly their 

 original flatness ; butin this last instance the teats are commonly 

 left larger, looser, and more pendulous than before, in conse- 

 quence of the reiterated extension of them by the foal : a circum- 

 stance on which we may rely with tolerable certainty for a 

 knowledge of this fact. In mares who have had several foals, 

 the udders continue prominent and pendulous, and possess a 

 flabby feel ; and this is a state we cannot well mistake. To- 

 wards the latter end of gestation this part undergoes further 

 evolution, swells and grows firm to the feel, and becomes dis- 

 tinctly visible as we stand behind the mare. Within a few days 

 of parturition secretion begins, and the udders grow turgid with 

 milk : they do not, however, acquire their full distention until the 

 foal has drawn them for a few days, from which time they main- 

 tain their volume with little variation during the period of lacta- 

 tion. Soon after the foal begins to forsake the teat, the secretion 

 of milk diminishes ; and this is followed by a contraction of the 

 bag, which goes on gradually until it has resumed nearly or 

 quite its former flatness. In a state of full evolution, the udders 

 assume a hemispherical form, and acquire a firm plump feel; at 

 other times they are soft, flabby, more or less pendulous, and 

 possess neither definite figure nor volume. 



Coverings. — The outer covering of the udders is an extension 

 from the common integuments of the belly. This is thin and 

 fine in its texture, is commonly black, and is cloathed with a few 

 long downy hairs, growing thinner as they approach the teat, 

 immediately around which the skin is without any hair. Under- 

 neath the skin, adhering to it by intervening cellular membrane, 

 is spread over the gland a white, elastic, ligamentous covering, 

 interspersed with several fibrous bands, which is derived from 

 the faschia superficialis abdominis : this serves to give support 

 and compactness to the glandular structure, and, in consequence 

 of detaching processes into the interior among the lobules, to 

 strengthen their inter-union one with another. 



Structure. — The interior of the udder exhibits a light yellowish 

 aspect, and evidently possesses a lobulated structure, held to- 

 gether by a fine cellular tissue, here and there interspersed with 

 granules of fat. It is constituted of glandular masses, irregular 

 in magnitude and form, and loosely connected one with another, 



