16 HENRY H. DONALDSON 



European species are much higher than those determined by 

 Fubini (see Donaldson '08, table 20) and so confirm my earlier 

 conclusions concerning the untrustworthy character of his records. 



TABLE 12 

 Ratios of the weight of the brain to the weight of the spinal cord. Averages from 



(G) THE PERCENTAGE OF WATER IN THE BRAIN AND SPINAL CORD 



Table 13 shows the condensed results on the percentage of 

 water. In my former communication I called attention to the 

 differences in this character in the several species (Donaldson 

 '08, p. 139.) 



While the percentages of water in both the brain and spinal 

 cord as determined for both European species in 1909 are less 

 than that found in R. pipiens, they are nearly alike, and also 

 similar to the 1904 determination for R. esculenta, so that it is 



