HEREDITY. 8t 
of species, though he had outlined them as early as 1801. 
The changes in the species have been wrought, he said, 
through the unceasing efforts of each organism to meet 
the needs imposed upon it by its environment. Constant 
striving means the constant use of certain organs, and 
such use leads to the development of those organs. Thus 
a bird running by the sea-shore is constantly tempted’ to 
wade deeper and deeper in pursuit of food; its incessant 
efforts tend to develop its legs, in accordance with the 
observed principle that the use of any organ tends to 
strengthen and develop it. But such slightly increased 
development of the legs ts transmitted to the offspring of 
the bird, which in turn develops its already improved legs 
by its individual efforts, and transmits the improved ten- 
dency. Generation after generation this is repeated, 
until the sum of the infinitesimal variations, all in the 
same direction, results in the production of the long- 
legged wading-bird. In a similar way, through indivi- 
dual effort and transmitted tendency, all the diversified 
organs of all creatures have been developed—the fin of 
the fish, the wings of the bird, the hand of man; nay, 
more, the fish itself, the bird, the man, even. . 
Note well, the fundamental assumption is that such 
acquired characteristics,—greater length of leg, or of 
neck, a coating of hair, a protective coloring, etc.,— 
howcver acquired, can be transmitted from the parent 
anitval-; ossessing them, to its offspring. The question 
arise. Can such characteristics be transmitted? And 
the «., lents of heredity answer: They cannot! 
I fiad in G. Archibald Reid “Alcoholism, a Study in 
Heredity,” a lucid exposition of this subject. (Reid is a 
F. R.S.E. His book was published by T. Fisher Unwin, 
London, a few years ago.) : 
‘All the characters of a living being, every physical 
' structure and every mental trait, may be placed in one of 
