118 ARTIODACTYLA. 



oblique muscles are pretty strong and broad, especially at their inser- 

 tion, which gives a difference in the obliquity of their fibres ; they are 

 inserted rather further back than the four first straight [muscles], and 

 [are inserted] before the others 1 . 



Of the Breasts or Udders. — The glands intended for the secretion of 

 milk are two, placed on the belly at its lower part, one on each side of 

 the middle line of the belly. They are flat bodies lying between the 

 external layers of fat and the muscles of the abdomen, are of consider- 

 able length, and in breadth only about one-fourth their length. They 

 are thin, that they might not vary the external shape of the animal. 

 They have a duct which runs the whole length of the gland in the 

 middle, collecting the smaller lateral ducts, which are the trunks of still 

 smaller ones. Some of these lateral branches enter in the direction of 

 the stream, others in a contrary direction, especially those nearest to 

 the last part of the great trunk. This trunk is very large, and would 

 appear to make a reservoir for the milk . It terminates entirely in a 

 projection, which is placed at the bottom of a sulcus or fissure which 

 covers it, and prevents it being a projecting part beyond the general 

 surface of the animal. The lateral parts of this sulcus are composed 

 of parts looser in texture than the common adipose membrane, similar 

 to the opening of the vagina, which probably admits of the elongation 

 or projection of the nipple. The nipples are on each side the opening 

 of the vagina 2 , in a small sulcus. On the outside of this there is another 

 smaller fissure, which I conceive is for the greater facilitating motion 

 in all these parts 3 . 



[Section Ungulata. 



Order Aktiodactyla. 



Suborder Non-ruminantia. 



Family SUIDjE.] 



The Common Hog [Sus Scrofa, Linn. 4 ]. 



Loose Notes on a Hog. 



At the entrance of the oesophagus of the common hog, the stomach 



i [Hunt. Preps. Nos. 1679—1684, 1777.] 



2 [The female organs are displayed in the Hunt. Preps. Nos. 2792 — 2794.] 



3 [Hunt. Preps. Nos. 3743, 3744.] 



4 [Various specimens of the osteology and odontology of the wild boar and 

 domestic hog are preserved in that part of the Hunterian Collection : Nos. 3254 — 

 3327.1 



