THE DESCENT OR OBIGIN OF MAN 197 



believe were possessed by his early progenitors. If the 

 origin of man had been wholly different from that of all 

 other animals, these various appearances would be mere 

 empty deceptions; but such an admission is incredible. 

 These appearances, on the other hand, are intelligible, at 

 least to a large extent, if man is the co-descendant with other 

 mammals of some unknown and lower form.- 



Some naturalists, from being deeply impressed with the 

 mental and spiritual powers of man, have divided the whole 

 organic world into three kingdoms — the Human, the Animal, 

 and the Vegetable — thus giving to man a separate kingdom.' 

 Spiritual powers cannot be compared or classed by the natu- 

 ralist; but he may endeavor to show, as I have done, that 

 the mental faculties of man and the lower animals do not 

 differ in kind, although immensely in degree. A difference 

 in degree, however great, does not justify us in placing man 

 in a distinct kingdom, as will perhaps be best illustrated by 

 comparing the mental powers of two insects, namely, a coccus 

 or scale-insect and an ant, which undoubtedly belong to the 

 same class. The difference is here greater than, though of 

 a somewhat different kind from, that between man and the 

 highest mammal. The female coccus, while young, attaches 

 itself by its proboscis to a plant; sucks the sap, but never 

 moves again; is fertilized and lays eggs; and this is its 

 whole history- On the other hand, to describe the habits 

 and mental powers of worker-ants would require, as Pierre 

 Huber has shown, a large volume; I may, however, briefly 

 specify a few points. Ants certainly communicate informa- 

 tion to each other, and several unite for the same work, or 

 for games of play. They recognize their fellow-ants after 

 months of absence, and feel sympathy for each other. They 

 build great edifices, keep them clean, close the doors in the 

 evening, and post sentries. They make roads as well as 

 tunnels under rivers, and temporary bridges over them, by 



' Isidore Geoflroy St.-Hilaire giyes a detailed account of the position assigned 

 to man by various naturalists in their classifications: "Hist. Nat GWn.," torn. 

 iL, 1859, pp. 170-189. 



