A Study of Cerebral Anthropology il 



when the etiological factor must have been operative than that 

 representing the time when the processes suggested by him are 

 active ; then too statistics will show that this condition is not the 

 usual result of these morbid conditions. 



Giacomini (1890), while admitting that microcephaly is a 

 reminder of the general law of development, does not think it can 

 be used in favor of the theory of descent, because it does not 

 stand for any period in man's development. 



The controversy as to whether microcephaly is a simple 

 arrested development or atavistic reminiscence is to find solution 

 when we can definitely state which characters are embryonal and 

 which are simian ; then, I believe, a study will show that the 

 brains of these defectives may be placed in different classes 

 depending on the preponderance of the characters. 



Relation of structure to function is another question for which 

 the solution has been sought in the microcephalic brain. Wagner 

 sought to interpret normal brain function through the variations 

 presented by these brains. Since Broca identified speech with the 

 third frontal convolution, it has been especially investigated in 

 microcephalic brains, but with negative results. No type of con- 

 volution or sulcus variation is constant in microcephaly even 

 among cases of similar mental deficiency. We may then ask of 

 what significance is convolution or fissure pattern from a psychical 

 standpoint, what significance has the presence of an unusual or 

 the absence of a usual convolution, what is the efifect on the mind 

 to bury a convolution normally on the surface or to elevate an 

 area commonly at the bottom of a furrow? The only answer 

 seems to be that the inferior mentality of the microcephalic is 

 expressed in a (usually) low brain weight and the more frequent 

 occurrence of unusual variations. Riidinger (1886) says, " Dass 

 ein Hirnorgan eine dem Grade seiner Thatigkeit proportionale 

 Ausbildung erfahrt"; and Marchand (1889) adds, "Das dem 

 Grade der Ausbildung eines Gehirnorganes audi dessen Func- 

 tion entspricht." But this is speaking only in the most general 

 terms. 



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