470 MAMMALIA. 



very small and simple in form. 'J'he families for our considera- 

 tion arc the Hiiiilif or Pigs, and the liuniinant families Qari- 

 rnniia or BoriiJ<r (Oxen), OcU^o (Shecii and (roats), and the 

 CerridcB (Deer). 



NON-R UMIXA .V TS { = B UXODOSTA). 



The non-ruminating Artiodactyla are often called Pachy- 

 dermata on account of the thiclc bristly skin, and have four 

 toes in the Hippopotamus touching the ground ; in the Pigs two 

 are rudimentary. The molars are tuberculate. 



The SuiD.E or Pigs have two functional toe.s, the other two 

 not touching the ground — the so-called " dew-claws " of the pig. 

 Now and then the first digit is present, arising from the tra- 

 pezium, but such cases are very rare. Canine teeth are large in 

 the males, forming the "tusks" of the boars. The teeth (fig. 

 244) vary in number in each species of pig. In the domestic 

 pig the dental formula is — 



3—3 1—1 3—3 4—4 



*3-3'^l^'^™§=3^ ™i=-4 = "- 



The stomach of the pig is simple like that of the horse, but less 

 curved on itself ; the oardia has a small conical dilatation, like a 

 cowl turned backwards. The capacity is from 1|- to 2 gallons. 

 The blunt snout is provided with a peculiar bone called the 

 " scooping-bone.'' The pig's intestine resembles that of the 

 ox ; it is 72 feet long. The mesentery that suspends the small 

 intestine contains an elongated mass of lymphatic glands, the 

 so-called mesenteric glantl. The caecum is sacculated as in the 

 horse, with three longitudinal muscle bands. The penis is 

 twisted spirally when flaccid. The testicles are round, and the 

 scrotum narrow and but little detached. ^Vt the prepuce is a 

 special pouch which secretes an unctuous fluid, which even 

 taints the flesh. The mammte are usually ten in number. In 

 the braiu there are few cerebral convolutions. There are fouiv 



