A Study of Cerebral Anthropology 9 



who have followed this idea evidently were not aware that Mar- 

 chand refuted the theory entirely. 



From time to time the theory of injury to the foetus, directly 

 of a mechanical or of a toxic nature, or indirectly through 

 maternal injury or through physical maternal shock, have been 

 presented with all the assurance of original discovery. There 

 remains the question of a pathological factor, which, if admitted, 

 leaves us as far from the exact truth as we were in the beginning. 

 ]\Iingazzini (1909) seems to favor the last. 



Aside from the basic cause of microcephaly we must consider 

 what it represents : and here there is a division of opinion between 

 a pathological manifestation, arrested development, and retro- 

 development or atavism. It seems to me that by following the 

 work of Giacomini and Cunningham, there should be no diffi- 

 culty in eliminating the question of pathology from microcephaly 

 proper, although Mingazzini (1909) says "an examination of the 

 brains of defectives indicates an arrest of development or the 

 ravages of pathology, the preponderance depending on the 

 dbserver." 



The majority of authors consider the condition as representing 

 an arrest of development, defined by Marchand as the result of a 

 disturbance which the brain has suffered at some time in its 

 development, causing development to stand still for a time, then 

 when it proceeds it is on a changed basis and hence maldevelop- 

 ment. Turner (1891) seems to agree with this idea when he 

 says that the brain of an idiot, no matter how deformed, is still a 

 human brain just as a deformed foot is still human. 



Retrodevelopment or atavism as the interpretation of micro- 

 cephaly was first urged by Vogt (1867). It is not sufficient to 

 quote the various authors who have written in favor of this 

 view of retrodevelopment without defining to some extent the 

 term atavism, for it seems to have been used with varying 

 interpretations. 



Vogt recognizes some factor producing an arrest of develop- 

 ment, that factor or another turns the process of development 

 from its normal channel into some ancestral one, till at the com- 

 pletion of development the brain is perhaps more simian than 



353 



