Abstract
IN his letter in NATURE of December 3, Dr. J. Needham suggested that “the chemical ground-plan [of development] must be thought of as deformable in space-time”. In this connexion, the deformations which are obtained by a change in the unit of time measurement seem to be particularly interesting. Needham showed that if we have two animals a and b and measure in each of them several chemical magnitudes Ma, Mb, Na, Nb, etc., such as fat content, dry weight, etc., we find relations of the type log Ma/Mao=k log Na and log Mb/Mb0=k log Nb where Ma0, Mb0, are specific constants and k is a general constant relating M and N for all animals. Now M and N are also functions of the time t. If we have log Ma/Ma0 = F(t) and log Mb/Mb0=F(t) we can clearly choose another variable p such that F(p)=f(t), That is to say, by choosing a suitable unit for the measurement of time, we can convert the growth curve of Mb into that of Ma: and further, the same system of time measurement will convert all the growth curves of chemical magnitudes of animal b into those of animal a, provided only that in each case there is the linear relation between the logarithms, with the general constant k which Needham discovered. Thus we could regard the two systems of time measurement defined by t and p as the relative time scales of chemical development of the two animals.
Similar content being viewed by others
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
WADDINGTON, C. Heterogony and the Chemical Ground-Plan of Animal Growth. Nature 131, 134 (1933). https://doi.org/10.1038/131134b0
Issue Date:
DOI: https://doi.org/10.1038/131134b0
This article is cited by
-
Hensen's node — The ’Organizer’ of the amniote embryo
Experientia (1976)
-
Primitivstreifen und Urk�rper nach St�rungs versuchen am 1?2 tage bebr�teten H�hnchen
Wilhelm Roux' Archiv f�r Entwicklungsmechanik der Organismen (1936)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.