
It may well be that I have missed the main points of the author’s biochemical argument, but if so, I think other readers would do so. To a biologist it would seem that the most important deductions from the theory arise when the ring of tissue (p.24) becomes very large, but the wave length is determined by chemical data (p.28). Presumably this is an approximation to what might happen in a long string of tissue, which would then form segments, of equal length ex- cept near the ends. The author might refer to this point. The treatment would be easier to follow were the assumptions made clear. It appears to be assumed throughout, for example (1) that morphogens cannot diffuse out of the organism, which they certainly do, e.g. in fungal cultures, and (2) that diffusion through a cell wall is very much slower than through the interior of a cell. Such assumptions should, I think, be stated. Again, the genetical theory of p.3 is rather insecure. In many embryos (e.g. embryo Salmonidae <u>fide<\u> Svardson) the chromosomes are much larger than in adult tissue, and in others (<u>fide<\u> Pasteels and Lison) the amount of desoxyribo-nucleic acid per cell is much greater. There is at least a <u>prima facie<\u> case that there may be a large number of examples of each type of gene in a given nucleus. As embryonic development is under consideration, this is important. Again, on p.62 ‘This is gastrulation’ seems an overstatement. Localized overgrowth might easily yield a pearshaped form, and the kinematics of gastrulation are, in fact, very complicated (cf. Vogt, Dalcq, etc.) The following is a probably incomplete list of errata: p.6. l.26 ‘1’ omitted. p.9. l.17 ‘equilib<u>t<\u>ium’ p.13.l. 2 ‘mo<u>t<\u>phogen’; l.8. ‘concentra<u>n<\u>tion’ p.15.l. 8 ‘u<u>sal<\u>ly’ p.16.l.11 ‘le<u>as<\u>t’; l.29. ‘mirro<u>w<\u>’ p.38.l. 9 ?R(t) and t omitted. p.47.l.25 ‘i<u>a<\u>’ p.50.l.4 ?’C’ omitted ? on p.30 l.1 = [half] and (8.3) to read
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Manuscript details
- Author
- Alan Turing
- Reference
- RR/1950-51/B62/2
- Series
- RR
- Date
- 1951
- IIIF
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Cite as
Referee report by J. B. S. Haldane on 'On the Chemical basis of Morphogenesis' by A. M. Turing, 1951. From The Royal Society, RR/1950-51/B62/2
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