DoNALDSON-ScHOEMAKER, Netvoiis System of Frogs. 127 



in proportion to those of the rest of the leg. Corresponding 

 with their greater weight, the proportional length of the legs in 

 virescens is somewhat greater — considering the several bones of 

 the leg, virescens has proportionately a slightly longer tibia, 

 while the femur and foot are slightly shorter. All the differences 

 in proportion are small however, and this is the more surprising 

 since when one compares the two forms in the living state, their 

 external appearance would not lead one to expect this close 

 correspondence. 



In general, we have to repeat the conclusion reached in the 

 case of the Bull-frog, namely ; that the weight of the leg mus- 

 cles as compared with that of the entire body is the only rela- 

 tion that varies regularly with the size of the frog, and even in 

 that case, the amount of variation is small. 



XIII. FuBiNi's Observations. 



In 188 1 Fubini^ published a series of observations under 

 the title : "Gewicht des centralen Nervensystems in Vergleich 

 zu dem Korpergewicht der Thiere, bei Rana esculenta und 

 Rana temporaria." 



To compare this study with our own, it will be necessary 

 to summarize Fubini's work. 



He examined both R. temporaria and esculenta using in 

 all forty eight specimens of each species, there being twenty 

 four of each sex. In all cases he determined the weight of the 

 body and of the central nervous system (brain and spinal cord) 

 as well as of the brain alone. The body weight in half of each 

 species was taken without disturbing the viscera of the thorax 

 or abdomen, while in the other half the specimens were com- 

 pletely eviscerated before weighing. 



He concluded that in both species the relative weight of 

 the brain and also of the entire central nervous system, was 

 greater in the males than in the females, a relation which, he 

 adds, is similar to that found in man. 



' Moleschott's Untersuchungen zur Naturlehre etc. Bd. XII. S. 455-461. 



