The nervous system of the American leopard frog, Rana pipiens, compared with that of the European frogs, Rana esculenta and Rana temporaria (fusca) / by Henry H. Donaldson.

  • Donaldson, Henry Herbert, 1857-1938.
Date:
1908
Catalogue details

Licence: In copyright

Credit: The nervous system of the American leopard frog, Rana pipiens, compared with that of the European frogs, Rana esculenta and Rana temporaria (fusca) / by Henry H. Donaldson. 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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    There is no good fixed point for the lower end, the one which has been adopted as the cut end, obtained by cutting across the leg through the knee joint at right angles to the axis of the leg when it is in full extension.” TABLE 17. R. temporaria. Length of No. OF Body Weight Sciatic in Specime.n. in Grams. mm. XXI 15.10 46.0 XXII 20.15 4S° XXIII *6-45 4SS XXIV 18.15 50.0 XXV 20.80 49.0 XXVI 24.80 53.5 Average .• 19.20 48.2 To compare with these, we have observations on four specimens of R. pipiens, made by Mr. TAKAHASHi^in the Neurological Lab- oratory of the University of Chicago. The specimens examined by Takahashi, and in which the inter- nodes were studied in the same locality as that selected by Boy- cott, were four in number, and the measurements made on them are given in the following table; TABLE 18. Sciatic Length No. OF Body Weight in m.m.* Speci.men. in Grams. (Calculated.) Ill : 26 49. V 34 53-3 VI 37 60.2 VIII 63 65.8 Average 40 57.3 * This measurement was not made by Mr. Takahashi, but has been calculated from other data in his tables. In accordance with Boycott’s results, we should expect in this series of R. pipiens, with an average sciatic length of 57.3 mm. to find longer internodes than in the series of R. temporaria, with an average sciatic length of only 48.2 mm., but on the contrary, the internodes in R. pipiens are much shorter. To make the com- parison fair however it is necessary to reduce the measurements on R. pipiens to the measurements of the R. temporaria series, * Mr. Takahashi kindly allows me to use the data from his forthcoming paper on the internodes in R. pipiens.