Further observations on the nervous system of the American leopard frog (Rana pipiens) compared with that of the European frogs (Rana esculenta and Rana temporaria) / Henry H. Donaldson.

  • Henry Herbert Donaldson
Date:
1910
Catalogue details

Licence: In copyright

Credit: Further observations on the nervous system of the American leopard frog (Rana pipiens) compared with that of the European frogs (Rana esculenta and Rana temporaria) / 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.

    9/22 (page 5)
    The foregoing tables (1-5), representing five series, contain the fundamental data. The plan was to have twelve specimens in each series. In the case of It. esculenta 1904 and also 1909, there are, however, only eleven in each. The absent records were excluded because the percentage of water, which was not calculated until my return home, showed the excluded specimens to be in abnormal condition. In the case of It. temporaria 1909 sixteen records were made. In general, the grouping of these data is by threes. There are however three exceptions: In It. esculenta 1904, with a total of 11 specimens, there is one group of two (Records 7 and 8) and in R. esculenta 1909, there is one group of two (Records 10 and 11). In R. temporaria 1909 there is one group of four. In each case this departure from the rule is indicated in the condensed tables (6, 10, 12, 13,) by a bracketed number following the average for body weight. It will be noted that in the 1904 series, the column under the heading “ Body length ” is vacant. This measurement was not made in that year, but was made in the specimens collected in 1909. It represents the length of the frog from the tip of the nose to the tip of the urostyle, the skin over the urostyle having been split in order to expose its cartilaginous tip; the measurement being taken with vernier calipers. In the previous paper (Donaldson ’08) some measurements on preserved material were introduced without correction for the effects of the reagents used. These cases were explicitly noted. It is of interest to state therefore that, in this paper, the data apply to the fresh material only. Indeed all the measurements were made on the material when fresh except in the case of the leg bones of the two 1909 series. In these cases the legs were brought to this country from Europe in 60 per cent alcohol and then the bones were measured. A long series of control observations on the legs of R. pipiens treated in the same way and for the same time have shown that