On the relation between the quantity of brain and the size of the body in vertebrates / by Eugène Dubois ; [communicated by H. Zwaardemaker].

  • Dubois, Eugène, 1858-1940.
Date:
1914
Catalogue details

Licence: In copyright

Credit: On the relation between the quantity of brain and the size of the body in vertebrates / by Eugène Dubois ; [communicated by H. Zwaardemaker]. 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.

    13/24 (page 11)
    657 substance varying' with the size. They ask themselves the question, if the law found for the Dog may in general also be applied to other species, and give a negative answer to it. “A priori, on doit estimer que non, et nous avons soin de dire que notre etude porte sur un cas particuher.” (p. 765). In conclusion they say: ‘T1 y a done, en passant des petits aux grands chiens, une difference sensible de la composition chimique, et, par suite, Tunite de poids ne repre- sente pas pour les uns et pour les autres des valeurs physiologiques identiques”, fp. 773). It is clear, that by Lapicque and by me, independently of each other and unprejudiced, an identical i-esnlt has been obtained for two very different species of Mammals. If this circumstance increases considerably the importance of this result, then it appears at the same time that neither of us surmised he had found an interindi- vidual exponent of correlation equal for all species. Calculating the value of r for the dog found by L.apicque, proportional to the number of observations used for each comparison’ afterwards’) communicated by him, I find it to be = 0.235. When he repeated the investigation applied to Man, which had caused me to find the two above mentioned values of r 0.245 and 0.219, with other evidences, according to the second method, he found for’ Man 0.23 and for Woman 0.224. A comparison of the averages of 7 larger with 7 smallm individuals of an AmeriCcUi Squirrel (Scinrus carolinensis), which 14 individuals with a smaller American species (Semrns carolinensis) (6 individuals) had furnished an exponent of correlation of 0.56, gave an interindividual exponent of 0.20 ^) With two groups of 5 female Moles of Manouvrier I fmd 0.234 •’)! The average of these seven observations is 0,228. A number of other comparisons, with less good evidences, however constantly furnished values that do not differ much from the average found in this way. When I compare the above-mentioned weights of the SIX largest Bullfrogs of Donaldson (1. c.) with the six next in size of the same species, I find an exponent of correlation of 0,2516. 0 “Le poids encepliahque en fonction du poids corporel entre individns d’une meme espece”. Bulletin et Memoiie.s de la Societe d’Anthropologie de Paris. Seance du B juin 1907. Serie, Tome 8, fasc. 4. Paris 1908, p. 315. 2) Lapicque, “Le poids encephalique en fonction du poids corporel entre individus d une meme espece 1. c. p. 327. ») There must be errors in Manouvriek’s statements (Memoires Soc. d’Anthron Pans 188o, p. 213 and p. 297) concerning two gi oups, each of 7,cf moles, as the heavy individuals should on an average only possess 1 m.g. more brain than the lio-hter one., the average hkewise points to these errors. Consequently these groups are usbIcss foi the calculcition of the interindividuciJ r