674 THE POPULAR SCIENCE MONTHLY. 



begin with some thoughts upon organic physiology in its general rela- 

 tions, as preliminary to the special results desired. 



The animal frame is a material organism which is kept in activity 

 by certain energies. These energies are constantly exhausted and con- 

 stantly renewed, but their vigor at any fixed period is limited, and can 

 not be indefinitely increased. The force received from without is vari- 

 ously employed within the organism. It acts successively as muscular, 

 nervous, temperature, and reproductive energy. But being limited in 

 quantity, if it be employed by any of these organic agencies, its use by 

 the others is restricted or prevented. Much of the energy received is 

 used up in alimentary processes — the pursuit, seizure, mastication, and 

 digestion of food. Only the excess over this is available for the other 

 organic necessities. And, if this excess force be exhaustively employed 

 by any one of the bodily agencies, it becomes unavailable for the 

 others. 



The fact here briefly stated is one which might be illustrated by 

 numerous instances drawn from the lower animal world. A very inter- 

 esting example of its influence may be perceived in the organic condi- 

 tions of the ants, and, to a lesser extent, in other insect tribes. Ants, 

 though possessed of all the organic force agencies, do not employ them 

 all in any one individual. The males and the fully developed females 

 exhaust all their life-force in reproduction, with little display of mus- 

 cular and none of mental vigor. The remaining members of the tribe, 

 divided into workers and soldiers, devote all their life-force to muscu- 

 lar and mental labor. They are, functionally, females, but their organic 

 energies are entirely withdrawn from the reproductive agencies, and 

 devoted to other life-purposes. Of these two classes the workers appear 

 to have the highest mental development. The soldiers understand 

 the whole business of fighting, but beyond that they seem incapable, 

 and take no part in the nest-building, the food-gathering, or any other 

 of the ant-industries. Indeed, they are too dull or too proud to even 

 feed themselves. They would starve unless fed by the workers or 

 slaves. And in the occasional ant-migrations the soldiers are carried 

 bodily by the workers, neither resisting nor aiding in the labor neces- 

 sary to move their high dignities. In the workers the exercise of mus- 

 cular force seems to be accompanied by a considerable employment of 

 mental energy, since they perform many actions which appear to indi- 

 cate an advanced intelligence. 



This illustration from the ants might be extended to the bees, and 

 to some other insects. We might also describe the very curious and 

 diversified separation of function in the members of the Siphonopho- 

 rcB, or compound polyps. But there is no occasion to multiply illus- 

 trations. If we ascend to the higher animals we find no such division 

 of function. And yet circumstances largely govern the extent to 

 which the organic force is applied in any one direction. But we must 

 make here a distinction which facts yet to be described render very 



