Anatomical Characters of the Human Brain. 27 



which there is a marked difference between the brains of men and 

 women may be tested by other records. For instance, according to 

 Rotzius the anterior branch of the fissure of Sylvius is divided and 

 forms an operculum frontale intermedium in 82 per cent of the brains 

 of men and in 100 per cent in those of women. At this point woman's 

 brain forms a perfect norm, being richer in all cases in gyri and sulci. 

 However, only four specimens of brains of women without an inter- 

 mediary operculum would have made the results for the two sexes 

 exactly alike. JSTo doubt a larger number of records would have 

 shown, even in Stockholm, that the operculum frontale intermedium 

 is not always present in the female brain. I notice that Karplus, in 

 the article mentioned above, figures four brains of women without the 

 operculum frontale intermedium, and states expressly that it is miss- 

 ing in those four specimens which were found in a relatively small 

 number of brains. His record will bring the chief difference, given 

 by Retzius, pretty close to the male average of 82 per cent. The second 

 criticism can only be made by collecting many more statistics along 

 the lines laid down by Retzius in his great monograph. 



At any rate what has been written by Karplus is to the point: 

 "Auf die von den Autoren angegebenen einzelnen Geschlechtsmerk- 

 male der Gehirne, die ja von vielen bestritten werden, will ich hier 

 nicht naher eingehen. Auch hier muss zunachst viel mehr Material ge- 

 sammelt werden, bisher bin ich nicht davon iiberzeugt, dass sich 

 aus dem Furchenbild eine Inferioritat des weiblichen Gehims ableiten 

 liesse." 



The question of the type of the female brain, a subject which 

 has been discussed so much, is therefore still far from being solved 

 in a satisfactory manner. 



Furthermore, it is by no means established that there are male 

 and female types of the brain due to the form and arrangement of the 

 gyri and sulci, as has been so frequently asserted. Each claim for 

 specific differences fails when carefully tested, and the general claim 

 that the brain of woman type is foetal or of simian type is largely an 

 opinion without any scientific foundation. Until anatomists can 

 point out specific differences which can be weighed or measured, or 

 until they can assort a mixed collection of brains, their assertions 



