On the individual difference of adult human cerebral motor area in macroscopic and histologic way

The brain was fixed with formalin, washed by water, dehydrated with alcohol and etheralcohol, inbedded in celloidin and then stained by Nissl's method. The cells larger than 27.5 were to be considered as the Betz-cells. The area, where the Betzcells were found, were regarded as the motor area and the schemata of 70 cases of motor cortex were made. The fact was cleared from those schemata, that in the vicinity of th motor area those, which showed similar macroscopic findings, had similar extension of the motor area. The schemata of the macroscopic figure of the motor cortex were classified into 5 types and each type had its own shape of the motor area. There were a few exceptions among them, but they had also some close relation to the sulci. Among the 70 cases, those. in which the sulcus praecentralis superior was the anterior border, had the majority of 72.9%. In about 60% of all cases the motor area on one hemisphere was similar to the other side.