77G ANATOMY OF VERTEBRATES. 



inguinal. In the burrowing Mole-rat the anterior nipple is on the 

 inside of the base of the fore-leg, the posterior one at the middle 

 of the inner side of the thigh. There are six teats in Bathyergus, 

 eight in Loncheres, Octodoit, and Dasyprocta, ten in Myoxus, 

 and Lepus ; twelve in the Hat and Mouse : even fourteen are said 

 to have been noted in the Agouti, but this is probably abnormal. 



The Insectivorous order yields the maximum number of nipples 

 in the mammalian class ; as many as twenty-two having been 

 observed in the tropical Hedgehog called Tenrec ( Centetes), and 

 the number rarely falls below fourteen. In such multiplica- 

 tion of teats and lacteal glands they extend along the under 

 surface of the body from the pectoral to the inguinal region ; 

 and, in some Shrews (Sorex crassicaudatus, e.g.), the last pair 

 of teats projects from the under side of the thick base of the 

 tail. In the common Hedgehog (Erinaceus) there are ten teats, 

 three pairs thoracic and two pairs abdominal, ranging from the 

 pectoral to the inguinal regions. The thin and flat mammary 

 glands seem to form a continuous stratum. In Shrews and 

 Moles the teats are from six to eight in number. In the volant 

 Insectivora they are usually reduced to two, and are pectoral in 

 position, whence Linnaeus was led to avail himself of this, with 

 another outward genital character, to unite Bats in the same 

 order (Primates) with Apes and Man. But the Sloths have one 

 pair of pectoral teats and mammary glands. Many Armadillos, 

 likewise, have two pectoral teats ; to which, in a few kinds 

 (D. novem-cinctus, e.g.), a pair of inguinal teats are added. The 

 two-toed Anteater has two pectoral and two ventral teats. The 

 great Anteater (Myrmecophaga jubata) is limited to two pectoral 

 mamma?. The young animal remains with the mother for the 

 space of a year, and is carried on her back. In a species of 

 PJiyllostoma I have seen two pubic as well as two pectoral teats. 

 The latter in all bats are almost laterally placed, and in Pteropus 

 are axillary : the nipple when in use becomes long, compressed, 

 and sub -pedunculate. The Colugo (Galeopitliecus volans) has t\vo 

 nipples in each arm-pit: they become large during maternity, for 

 the young cling long to them. 



Among Lissencephala the Rodents are most remarkable for 

 nidificatory instincts. The little Harvest-mouse (Mus messorius) 

 builds a round nest, like a Tit's, and attaches it, high up from 

 the ground, to the stems of full grown rye, barley, or other cereal. 

 The nest of the Marsh Hare (Lepus palustris) is formed of a 

 large kind of rush (Juncus ejfusus), cut into pieces about a foot 

 in length, and is arched over; the foundation of the nest is 



