358 THE POPULAR SCIENCE MONTHLY. 



of the origin of the conscience from the side of natural history. He 

 deems it to have had its beginning- when an animal could contrast the 

 transient pleasui-e given by the gratification of a passion -with the 

 abiding pain afterward felt. An enlargement of memory must have 

 come before the immediate and remote effects of actions could be com- 

 pared in consciousness, and the greater good recognized and chosen. 



This theory of conscience, which holds it to have been created by 

 the experiences of the race confirming habits best suited for social Hfe, 

 well accords with the theory of morals which takes benefit or utility, 

 in its largest sense, as the test and sanction of right conduct. 



While the manifestations of heredity in their obvious effects are 

 interesting, yet the laws brought to light by an examination of some 

 results apparently exceptional and contradictory are of still .deeper in- 

 terest. A single great law may underlie a large group of problems, 

 yet many other principles of minor weight may cooperate with it and 

 obscure its direct force. The study of residual phenomena is ever 

 fraught with increased knowledge and the unfailing testimony that 

 where law seems to be at fault it is only so from our ignorance of 

 the varied energies at work, which are constantly revealed to the pa- 

 tient searcher for truth. In the science of heredity many apparent 

 anomalies have been resolved in allowing for the action of forces newly 

 discovered or applied. 



The study of the unconscious powers of the mind has of late years 

 attracted much attention ; observation has found that there may lie 

 latent in a man tendencies and forces whose existence he may never 

 suspect, but which he is capable of transmitting to children who shall 

 palpably develop them. Insanity, gout, and melancholia, frequently skip 

 a generation and reappear when hopes have been entertained that the 

 evil trait had died out in the family. A son may resemble his mother 

 very markedly, and have children with the features and character of 

 his father. The evidence of heredity is thus borne out frequently in 

 the long-run, when to a contracted view it would seem at fault. An 

 individual inherits not only from his parents but from all their prede- 

 cessors in the line of life, and just what of them shall appear evidently 

 in him, and what be hidden in unconsciousness, none can tell. The 

 surface forces of the man may be like the momentum of a tree falhng 

 down a mountain-slope, but the inner and donnant powers never to be 

 manifested during a lifetime may as far transcend the energies actually 

 shown as the force of the fire which the tree may feed excels that of 

 its mere bodily impact in descent. 



The dormancy of traits accounts for atavism or the reversion of an 

 organism to the form and character of ancestral stock. Pigeons, dogs, 

 and horses, frequently relapse, so to speak, to the inferior type from 

 which they have been bred, and so exhibit a wide divergence from their 

 immediate parents. Reversion of this kind has been noticed in the 

 silkworm after a hundred generations. So long in Nature does an 



