CLASS I. MAMMALIA; ORDER 1. BIMANA. 
37 
only animal whose sense of smell is sufficiently delicate to be offended by unpleasant odors. Deli- 
cacy of smell must influence that of taste; and man must have a further advantage, in this re- 
spect, at least over those animals whose tongues are covered with scales. Lastly, the nicety of his 
touch results both from the delicacy of his teguments and the absence of all insensible parts, as 
well as from the form of his hand, which is better adapted than that of any other animal for suit- 
ing itself to the small inequalities of surfaces. 
Man has a particular pre-eminence in his organ of voice : of all mammalians, he can alone artic- 
ulate sounds ; the form of his mouth and the great mobility of his lips being probably the cause 
of this, Hence results his most invaluable mode of communication ; for of all the signs which can 
be conveniently employed for the transmission of ideas, variations of sound are those which can 
be perceived at the greatest distance, and in the most various directions, simultaneously. 
It seems that even the position of the heart and of the great vessels boars reference to the ver- 
tical carriage. The heart is placed obliquely on the diaphragm, and its point inclines to the left, 
thereby occasioning a distribution of the aorta differing from that of most quadrupeds. 
The natural food of man, judging from his structure, appears to consist principally of the fruits, 
roots, and other succulent parts of vegetables. His hands afford every facility for gathering them ; 
his short and but moderately strong jaws on the one hand, and his canines being equal only in 
length to the other teeth, together with his tuberculated molars on the other, would scarcely per- 
mit him either to inasticate herbage or to devour flesh, were these articles not previously pre- 
pared by cooking. Once, however, possessed of fire, and those arts by which he is aided in seiz- 
ing animals or killing them at a distance, every living being was rendered subservient to his nour- 
ishment, thereby giving him the means of an indefinite multiplication of his species. 
His organs of digestion are in conformity with those of manducation : his stomach is simple ; 
his intestinal canal of mean length ; his great intestines well marked ; his csecum short and thick, 
and augmented by a small appendage ; and his liver divided only into two lobes and one small one. 
To complete this abridged statement of the anatomical structure of man, necessary for this In- 
troduction, we will add that he has thirty-two vertebra?, of which seven belong to the neck, twelve 
to the back, five to the loins, five to the sacrum, and three to the coccyx. Of his ribs, seven pairs 
are united to the sternum by elongated cartilages, and are called true ribs ; the five folloAving pairs 
are denominated false ones. His adult cranium consists of eight bones : an occipital ; two tempo- 
ral ; two parietal ; a frontal ; an ethmoidal, and a sphenoidal. The bones of his face are fourteen 
in number : namely, two maxillaries ; two jugals, each of which joins the temporal to the maxil- 
lary bone of its own side by a sort of handle named the zygomatic arch ; two nasal bones ; two 
palatines, behind the palate ; a vomer, between the nostrils ; two turbinated bones of the nose in 
the nostrils ; two lachrymals in the inner angles of the orbits, and the single bone of the lower 
jaw. Each jaw has sixteen teeth : four cutting incisors in the middle, two pointed canines at the 
corners, and ten molars with tuberculated crowns, five on each side — in all, thirty-two teeth. His 
blade-bone has at the extremity of its spine or projecting ridge a tuberosity, named the acromion, 
to which the clavicle or collar-bone is connected, and over its articulation is a point termed the 
coracoid process, to which certain muscles are attached. The radius turns completely on the cu- 
bitus or ulna, owing to the mode of its articulation with the humerus. The wrist has eight bones, 
four in each range ; the tarsus has seven ; those of the remaining parts of the hand and foot may 
be easily counted by the number of digits. (See figure, p. 32.) 
PHYSICAL AND MOEAL DEVELOPMENT OF MAN. 
The ordinary produce of the human species is but one child at a birth ; for in five hundred 
cases of parturition, there is only one of twins, and more than that number is extremely rare. 
The period of gestation is nine months. A foetus of one month is ordinarily an inch in height; 
at two months, it is two inches and a quarter ; at three months, five inches ; at five months, six 
or seven inches ; at seven months, eleven inches ; and at nine months, eighteen inches. Those 
which are born prior to the seventh month usually die. The first or milk teeth begin to appear 
a few months after birth, commencing with the incisors. The number increases in two years to 
twenty, which are shed successively from about the seventh year, to be replaced by others. Of 
