. Comparative anatomy of vertebrates. Anatomy, Comparative; Vertebrates. INTEGUMENT 37 a papilla, while the surrounding skin remains almost on a level with the rest of the integument (c). In the latter case, therefore, there is an evagination of the mammary pocket, and the teats may be described as secondary or true (Marsupials, Rodents, Lemurs, Monkeys, and Man), and in the former as primary or pseudo- teats (Carnivores, Pigs, Horses, and Ru- minants). The latter condition is already in- dicated in certain Mar- supials ( Phalangista vulpina). The teats- are often situated in two nearly pa
. Comparative anatomy of vertebrates. Anatomy, Comparative; Vertebrates. INTEGUMENT 37 a papilla, while the surrounding skin remains almost on a level with the rest of the integument (c). In the latter case, therefore, there is an evagination of the mammary pocket, and the teats may be described as secondary or true (Marsupials, Rodents, Lemurs, Monkeys, and Man), and in the former as primary or pseudo- teats (Carnivores, Pigs, Horses, and Ru- minants). The latter condition is already in- dicated in certain Mar- supials ( Phalangista vulpina). The teats- are often situated in two nearly parallel rows along the ventral side of the thorax and abdomen which slightly converge towards the inguinal region ( Carnivores, Pigs) : in other cases they may be restricted either to the inguinal (Ungulates and Ceta- ceans) or to the thoracic region (Sloths, Manis, rjlephants, oirenia, JTIG 09. — DIAGRAMMATIC REPRESENTATIONS OF many Lemurs, Cheirop- THE EARLY DEVELOPMENT OF THE LEADING " TYPES OF MAMMARY GLANDS. (Modified from ueeenbaur.). B G tera and Primates): , .,' . , . while m others, again, they mav be axillary or i j • • i abdominal, or they may OCClir in various com- binations of all these > first or undifferentiated (mammary pocket) stage ; B, stage of the pseudo- (primary) teat ; ^ |tage 'of thfee true (secondary) teat ; d, mam- mary canal ; , glandular area; gl, mammary glands ; v, rim (or rampart) of the glandular area. regions. The number of teats varies greatly : there may be as few as one pair, or as many as eleven pairs (Centetes) : in general, their number corresponds to that of the young produced at one birth. Not infrequently, supernumerary or accessory mammae and teats can be recognised ( in Sheep and Cattle), and there may be indications in the foetus of a greater number of teats than that which occurs in the adult: thus in the embryo of Whalebone- Whales there are eight pairs, while the adult possesses only a single pair on either
Size: 1405px × 1777px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectanatomycomparative
