Literary Notices. cix 



writing are located in one hemisphere only; 2nd, morphologically 

 similar portions of the body may simultaneously perform physiologic- 

 ally dissimilar acts. 



C. H. T. 



The Brains of Microcephalic Idiots. 1 



Professor Marchand's studies were made upon three microceph- 

 alic brains, which, for convenience I will name brains I, II and III. 



No. I was the brain of Carl Koch, a boy four years and ten 

 months old. Weight of brain, including the membranes 890 g. 

 Length 15.5 cm. 



No. II was the brain of a man 40 years of age. Weight of brain, 

 including membranes, 870 g. Weight excluding membranes, 603 g. 

 Length of right hemisphere 13 cm. Length of left hemisphere 

 13.3 cm. 



No. Ill was the brain of Augustin Heil, age 33 years. Weight 

 of hardened brain 424 g. Length of the right hemisphere 11. 7 cm. 

 Length of left hemisphere n. 6 cm. 



These investigations establish a number of interesting facts : 



1. Compared with the normal human brain, these microcephalic 

 brains are very small, bram No. Ill, being only about one third as 

 heavy as the average male brain. Indeed this brain is but a very 

 little larger than that of a gorilla or a large sized chimpanzee. 



2. There is a great tendency to simplify and obliterate convolu- 

 tions. 



3. The central fissure tends to become vertical, indeed in No. I 

 and II it has fused with the sylvian fissure. 



4. In two cases the isle of Reil is exposed. This is a reversion 

 towards the type found in the lower apes. 



5. In brain I, the rudimentary condition of the 1st and 2nd oc- 

 cipital convolutions reminds one of the brains of the lower apes. 



6. The abnormally constructed diminutive occipital lobe, bears a 

 more or less developed operculum occipitale. 



7. In brains II and III there is a marked foreshortening of the 

 callosum. 



'Felix Marchand. Beschreibung drier microcephalen Gehirne. Nova 

 Acta d. Ksl. Leop. -Carol. Deutschen Akademie. Bd. LIII, No. 3 (1889). Bd. 

 LV, No. 3, (1890). 



