AUTHOR’S ABSTRACT OF THIS PAPER ISSUED BY 
THE BIBLIOGRAPHIC SERVICE DECEMBER 15 
COMPARATIVE STUDIES ON THE GROWTH OF THE 
CEREBRAL CORTEX 
II. ON THE SIZE AND SHAPE OF THE CEREBRUM IN THE NORWAY 
RAT (MUS NORVEGICUS) AND A COMPARISON OF THESE WITH 
THE CORRESPONDING CHARACTERS IN THE ALBINO RAT 
NAOKI SUGITA 
The Wistar Institute of Anatomy and Biology 
TWO FIGURES AND TWO CHARTS 
In connection with an earlier study on the size and shape of 
the cerebrum in the albino rat (Sugita, ’17), I took up a study of 
the changes in the size and shape of the cerebrum in the Norway 
rat during its growth. The method of investigation which was 
adopted by me for the albino rat, was followed in this case also, 
so that for these methods it is only necessary to refer to the 
paper just cited. 
Table 1 shows the body and the brain measurements of the 
Norway rats which were used. The individuals have been 
grouped according to their brain weights and the average meas- 
urements for each group are given in the table. To distinguish 
these from the like groups for the albino rat, which will often be 
referred to for comparison, a capital letter N was attached to 
every Norway rat group number. A large part of this material 
has been used for further studies on cortical development or for 
other purposes. Inasubsequent paper the individual data will 
be presented, so that the average values alone are here printed. 
The material, consisting of 62 Norway rats (43 males and 19 
females) whose brain weights fall between 1.1 grams and 2.4 
grams, was collected from time to time in the city and vicinity of 
Philadelphia from April to November, 1916. 
Figures 1 and 2 show the dorsal and laterai views of the Nor- 
way rat brain, on which the positions of the five diameters to be 
1 
THE JOURNAL OF COMPARATIVE NEUROLOGY, VOL. 29, No. 1, 
FEBRUARY. 1918. 
