A comparison of the white rat with man in respect to the growth of the entire body / by Henry H. Donaldson ; [in collaboration with Elizabeth Hopkins Dunn and John B. Watson].

  • Henry Herbert Donaldson
Date:
1906
Catalogue details

Licence: In copyright

Credit: A comparison of the white rat with man in respect to the growth of the entire body / by Henry H. Donaldson ; [in collaboration with Elizabeth Hopkins Dunn and John B. Watson]. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    EXPLANATION. In the original drawing, i ram. = i gram of body-weight in the rat, laid off on the ordinate to the left; and i mm. = 250 grams of body-weight in man, laid off on the ordinate to the right in kilogTams. On the base-line, 1 mm. = 1 day of rat life, 12.15 mm. = 1 year of human life, and the zero-point is taken at the time of birth. To the left of the zero-point, 21 mm. are laid off, corresponding to the 21 days of gestation for the rat; and 9.4 mm. are laid off, corresponding to the 285 days of gestation for The point of conception ( C) coincides for the two curves . but as gestation in man is relatively only half as long as in the rat, and as the ages arc in both cases counted from birth, the two curves are some- what displaced, so that the 30th year of human life falls a little to the left of the 365th day of rat life. The lines showing body-weights are heavier for man than for the rat, and in each case the curve for the male is indicated by the solid line, and that for the female by the broken one. For the records before birth no distinction for sex is made, and the solid line is used. Where the curves for the two sexes run close together, the distances have been exaggerated in some instances in order to keep the lines distinct. Chart reduced to one-third of the original dimensions Boas Anniversary Volume.