2 NAOKI SUGITA 
TABLE 1 
Giving average values of the physical measurements for a series of Norway rats 
arranged according to brain weight groups. Sexes combined 
Mer Gar oe Brees °F | sopy weIGcHT | BoDy LENGTH | TAIL LENGTH | BRAIN WEIGHT 
grams mm. mm. grams 
N XI 9 1) 7 86 47 1.161 
N XII 0 
N XIII 2 35.5 109 87 1.356 
N XIV 2 37.0 113 90 1.436 
N XV 5 52.6 126 104 1.536 
N XVI 8 65.8 136 118 1.644 
N XVII 8 93.8 157 129 1.743 
N XVIII + 131.9 166 148 1.836 
N XIX 3 193.1 187 164 1.965 
N XX 5 250.9 212 179 2.033 
N XXI 4 296.1 223 189 2.164 
N XXII 1 336.8 223 182 2.266 
N XXIII 1 394.0 256 202 2.345 
measured are designated. The dimensions of the figures are in 
accordance with the data given in table 2 and the figures are 
comparable with figures 1 and 2 given in the study on the albino 
rat brain (Sugita, 717). 
Table 2 shows the average values of the five diameters of the 
Norway cerebrum, measured at the same locations as in the case 
Fig. 1. Dorsal view of the Norway rat brain weighing 1.64 grams—enlarged 
1.8 diameters. To show the positions at which the two measurements for the 
width and the two measurements for the length were taken. 
Fig. 2. Lateral view of the Norway rat brain weighing 1.64 grams—enlarged 
1.8 diameters. To show the position at which the height was measured. 
