THE OKGANIC CELL 
47 
problem of heredity, but only of a certain aspect of it — the 
transmission of acquired characters, which has been hitherto 
assumed to occur. In taking this course I may say that it 
was impossible to avoid going back to the foundation of all 
phenomena of heredity, and to determine the substance with 
which they must be connected. In my opinion this can only 
be the substance of the germ-cells, and this substance transfers 
its hereditary tendencies from generation to generation, at 
first unchanged, and always uninfluenced in any corresponding 
manner by that which happens during the fife of the individual 
which bears it. 
‘ If these views be correct, all our ideas upon the trans- 
formation of species require thorough modification, for the 
whole principle of evolution by means of exercise (use and 
disuse) as professed by Lamarck, and accepted in some cases 
by Darwin, entirely collapses.’ (See ‘ Essays on Heredity/ 
vol. i., by A. Weismann, Clarendon Press, Oxford, 1889.) 
Continuing in the same line of thought, he maintains the 
absolute impossibility of acquired characters being trans- 
mitted, and also how inconceivable it is that changes in the 
body or ‘ soma ’ should affect the protoplasm of the germ- 
cells in such a manner as to produce similar changes in the 
offspring. He asks — How is it possible that the dexterity in 
the hand of a piano-player can so affect the structure of the 
germ-cells as to produce an equivalent dexterity in the hand 
of the child ? 
Weismann, in fact, maintains that none of the so-called 
cases of transmission of acquired characters will stand a 
scientific test. 
The child inherits from the parent germ-cell, not from the 
parent body, and the germ-cell owes its characteristics not to 
the body which bears it, but to its descent from a pre-existing 
germ-cell of the same kind. From the point of inheritance, 
the body merely carries the germ- cells, which are as it were 
held in trust for the development of future generations. 
According to Sir Michael Foster, the animal body is in reality 
a vehicle for ova ; and after the life of the parent has become 
potentially renewed in the offspring, the body remains as a 
cast-off envelope whose future is but to die. 
