microcephalia idiot with bilateral porencephaly. 499 
the mesial aspect of the right occipital lobe, associated with 
absence of the right external geniculate body, and with an 
especially attenuated left optic nerve, lead one to expect to hear of 
some visual defects, but no precise information is available on this 
subject. The recent appearance of the clot within the right lateral 
ventricle (descending cornu) suggests that death was due to an 
increase of intra-cranial pressure following the perforation of the 
attenuated cerebral wall and the effusion of blood into the 
ventricular cavity of the right side. 
It is important to note that Dr Wigglesworth expressly avoids 
an appeal to any developmental defect, as having determined the 
loss of cerebral substance in the case described by him: whereas he 
ascribes the cerebral defects to obstructive vascular lesions occur- 
ring in intra-uterine life {op. cit. p. 133). In both his specimen 
and mine, the porencephalic condition was, however, combined with 
microcephaly. In the case I describe, the porencephalic modifica- 
tions and the concomitant destruction of the occipital end of the 
right hemisphere, were almost certainly due to vascular lesions. 
The latter can also be held responsible for the curious microgyrous 
condition of the cortex of the temporal lobes. It is well to bear 
in mind the emphatic warning given by Dr A. W. Campbell 
(Brain, Vol. xxviil, 1905, p. 437), against the indiscriminate 
invocation of “developmental defects” as the causal factors in 
producing “ microgyry.” In the present case it would seem 
probable that the vascular lesions that determined “porencephaly” 
also brought about the microgyrous appearances. But the micro- 
cephalic condition affects the frontal lobes (which are not poren- 
cephalic) and the spinal cord was also asymmetrical and “ micro- 
myelic.” These microcephalic features of the case appear to me 
to denote a factor different from the vascular degeneration to 
which allusion has just been made, and this factor I believe to be 
deficient power of growth. 
Another brain closely resembling that which I describe, is 
figured in Professor Starr’s Organic Nervous Diseases (1903, 
Fig. 220, p. 536) where it is referred to as “Ferraro’s” example, 
without further reference to the original description. The case 
described by Dr Hannay ( Glasgow Medical Journal, Vol. lxi., 
No. 3, March 1904) bears some resemblance in so far as the asym- 
metry of the hemispheres, midbrain, and bulb were concerned ; 
but the frontal lobe of the left hemisphere was chiefly affected. 
In certain features, such as asymmetry of the cerebral 
hemispheres and of the pyramidal tracts, the Cambridge specimen 
presents resemblances to the case so admirably described by 
Schroeder van der Kolk ( New Sydenham Society: Selected 
Monographs, 1861). In the latter instance, no abnormality of the 
optic nerves is recorded. In the publication to which reference 
33 
VOL. XIV. PT. V. 
