NERVOUS SYSTEM OF THE FROG 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 R. esculent a 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 R. temporaria 1909 sixteen records were made. 

 In general, the grouping of these data is by threes. There are 

 however three exceptions: In R. 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 



