128 Journal of Comparative Neurology. 



Before showing that both these conclusions are wrong, we 

 will indicate one or two general points suggested by his tables. 

 These show that R. esculenta has a smaller brain weight than 

 R. temporaria. 



As an example we give below his averages of the body- 

 weight of twelve males of each species (not eviscerated) to- 

 gether with the corresponding averages for thp weights of the 

 brain. To these we may here add for comparison the brain 

 weight of one specimen of R. catesbiana and one specimen of 

 R. virescens brachycephala. 



TABLE Xn. 



The table shows the higher brain weight in temporaria as 

 compared with esculenta and the much higher weight in both 

 the American species. 



Fubini's tables do not permit us to say anything concern- 

 ing the weight of the spinal cord in the species examined by 

 him. The reasons for this are the following : He gives, to be 

 sure, the weight of the cord and brain taken together and then 

 of the brain alone. He uses the term brain as we have used it 

 and also seems to have taken the same boundaries for the cord 

 as those employed by us. This being the case the difficulty 

 presented by his tables may be illustrated in the following nian- 

 ner. For the twelve male R. temporaria quoted in Table XH, 

 he gives the average body- weight as 23.2 grams; the average 

 for the weight of the entire central nervous system as 133 milli- 

 grams and for the brain, 74 milligrams. By subtraction we get 

 the weight of the spinal cord as 59 milligrams. 



This is an impossible number and his other tables also give 

 values in all cases entirely too large. With the frogs he exam- 

 ined we have every reason to expect a weight for the spinal 

 cord which shall be not much more than half, and usually de- 

 cidedly less than half, the weight of the brain. This expecta- 



