microcephalia idiot ivitli bilateral porencephaly. 489 
the corpus callosum. The total area of the section is abnormally 
small. The descending and posterior cornua of the lateral ventricle 
are filled with blood clot which appears to be of recent formation. 
The cortex on the inferior (tentorial) aspect of the section is 
not convoluted. On the lateral aspect the posterior end of the 
first temporal gyrus is seen to be greatly attenuated. The grey 
cortical matter varies in depth from 31 mm. on the lateral 
convexity (parietal region) to ’9 mm., the latter measurement 
being derived from the cortex of the first temporal gyrus. Cortex 
of intermediate thickness (T2 mm.) is found on the lateral 
convexity and on the tentorial aspect. 
The cerebellum. 
This, like the cerebrum, is shrunken, owing to the action of 
the alcohol in which the brain has been immersed. The maximum 
transverse diameter (81 mm.) is less than that of normal cerebella. 
No marked asymmetry between the two hemispheres is noticed. 
The flocculi are imperfect, having been damaged in the 
removal of the encephalon from the skull. There is no appear- 
ance indicative of any divergence in size from the corresponding 
organs in normal brains. The distinction of flocculus and para- 
flocculus is not evident. A sagittal section through the vermis 
reveals the fissura prima and the fissura secunda as in the normal 
cerebellum. 
The mid-brain (Fig. 11). 
Fig. 11. The thick line is a tracing of the mid-brain of 
the microcephalic subject. The larger area with 
the finer contour-line is from a normal brain, shew- 
ing the greater size in the latter case ( x 2 diam.). 
