VERTEBRATA. 



the twelve posterior molars, which are permanent, there are four which make their appearance at 

 four years and a half, tour at nine years; the last lour being frequently not cut until the twentieth 

 year. 



The foetus grows more rapidly in proportion as it approaches the time of birth. The infant, on 

 the contrary, increases always more and more slowly. It has upward of a fourth of its height 

 when horn, attains the half of it at two years and a half, and the three-fourths at nine or ten years. 

 By the eighteenth year the growth almost entirely ceases. Man rarely exceeds six feet, and sel- 

 dom remains under five. Woman is ordinarily some inches shorter. 



- arcely has the body attained its full growth in height before it commences to increase in 

 hulk: fat accumulates in the cellular tissue. The different vessels become gradually obstructed; 

 the solids become rigid ; and after a life more or less prolonged — more or less agitated — more or 

 less painful —old age arrives, with decrepitude, decay, and death. Man rarely lives beyond a hun- 

 dred vears; and most of the species, cither from disease, accidents, or merely old age, perish long 

 before that term. 



The child needs the assistance of its mother much longer than her milk, whence results an ed- 

 ucation intellectual as well as physical, and a durable mutual attachment. The nearly equal num- 

 b i of individuals of the two sexes, the difficulty of supporting more than one wife, when wealth 

 docs not supply the want of power, intimate that monogamy is the natural condition of our 

 species; and as, wherever this kind of union exists, the sire participates in the education of his 

 offspring, the length of time required for that education allows the birth of others, whence the 

 natural perpetuity of the conjugal state. From the long period of infantile weakness results dc~ 

 mestic subordination, and, consequently, the order of society at large, as the young persons which 

 compose the new families continue to preserve with their parents those tender relations to which 

 they have so long been accustomed. This disposition to mutual assistance multiplies to an almost 

 unlimited extent those advantages previously derived by isolated man from his intelligence ; it has 

 assisted him to tame or repulse other animals, to defend himself from the effects of climate, and 

 thus enabled him to cover the earth with his species. 



In other respects, man appears to possess nothing resembling instinct— no regular habit of in- 

 dustry produced by innate ideas; all his knowledge is the result of his sensations, his observations, 

 or of those of his predecessors. Transmitted by speech, increased by meditation, applied to his 

 --iti'-s mid his enjoyments, they have given rise to all the arts. Language and letters, by 

 preserving acquired knowledge, arc a source of indefinite perfection to his species. It is thus that 

 he has acquired ideas, and made all nature contribute to his wants.* 



STRIKING CHARACTERISTICS OF THE HUMAN RACE. 



It is a remarkable fact, and worthy of particular notice, that in the economy of his body 

 m.iu is endowed with the ability to live on almost any part of the globe, and of thriving alike in 

 either extreme of natural \< mperature. Thus the Greenlanders and Esquimaux have reached 

 between 70° and 80° N. latitude, while the negro of Africa and the red man of America live 

 under the equator. But even Europeans, accustomed to a temperate climate, can bear either of 

 these extremes of cold and heat, as has been sufficiently proved by the numerous instances in 

 which those who have gone on the Arctic expeditions have been obliged to winter in high north- 

 ern latitude-; ami, on the other hand, by the slight degree in which European settlers in the 

 si parts of Africa are influenced by the temperature. 



Man subsists with equal facility under various degrees of atmospheric pressure — as well in the 

 deepesl valleys a- upon the most elevated table-lands. In correspondence with his ability to in- 

 habit every zone, he is able to subsist on the most varied food. In these respects he stands alone. 

 Bui however widely he may be distinguished from other animals in the peculiarities of his struc- 

 ture and economy, yet the sentiments, feelings, sympathies, internal consciousness, and mind, and 

 the habitudes of life and action thence resulting, are the real and essential characteristics of hu- 

 manity. I he difference in these respects between man and all other animals is indeed so great 



* Cuvier's !l Animal Kingdom." 



