XVII 
HAS THE CENTRAL NERVOUS SYSTEM ANY INFLU- 
ENCE UPON THE METAMORPHOSIS OF LARVA:?? 
Gustav TornieR has just published a hypothesis which 
is to explain how the acquired characteristics of parents are - 
inherited by their offspring. This hypothesis is as follows: 
In the more highly organized animals every adaptation of a 
functioning peripheral end-organ is accompanied by a corresponding 
and equal adaptation in the central nervous system; the central ner- 
vous system carries the acquired characteristic to the sexual organ, 
which forms with it a functional and nutritive unit, especially to 
the sexual cells, in that it compels the latter to undergo similar 
transformations. If the sexual cells give rise to new individuals, 
the descendants inherit the acquired characteristics of the parents.’ 
Tornier’s paper is very clear, and even though I cannot 
agree with his hypothesis, I consider it important that 
Tornier through his precise presentation of his subject has 
directed the attention of investigators to the question of the 
significance of the central nervous system in the processes 
of development. 
If Tornier’s idea is correct, then every alteration in the 
central nervous system must be accompanied by a similar 
change in the end-organs. Before the appearance of Tornier’s 
paper I had already made a series of experiments in which 
I divided the spinal chord of Amblystoma larvae in order to 
determine whether in the change of the larvee to the sexually 
mature form the animals with the divided spinal cord would 
behave as one or two separate animals; in other words, 
whether in an animal with a divided spinal cord the meta- 
morphosis of the interior and the posterior portions would 
occur simultaneously as in the case of the uninjured animal. 
1 Archiv fiir Entwickelungsmechanik der Organismen, Vol. IV (1896), p. 502. 
2" Uber Hyperdaktylie,” etc., ibid., Vol. III, p. 180. 
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