3.84 
POPULAR SCIENCE REVIEW. 
convolutions varies greatly. Complex convolutions are probably 
more important than the thickness of the sheet of grey matter, 
because it is obvious that not only quantity but activity of 
texture will be an advantage ; and complexity of convolutions 
involves increased surface of vascular membrane, sending its 
blood-vessels into the grey matter, and furnishing its elements 
with the means of activity. In harmony with this supposition, 
the simplest condition of the convolutions has been found in the 
brains of the lowest races of humanity, and Wagner’s comparisons 
of the brains of various persons of ability with others from 
persons of supposed limited intelligence show more complicated 
convolutions in the former than the latter, although at the same 
time exhibiting apparent exceptions to that rule. It may be 
noticed in this connection, that if two skulls of the same cranial 
capacity be one long and narrow and the other short and broad, 
the long and narrow one is that which has the greatest amount 
of surface, and is therefore most favourable for a large propor- 
tion of grey matter ; so that, ceteris paribus, the long skull has 
probably an advantage over the broad skull ; while, on the other 
hand, there is no doubt that, with a given model of skull to 
start from, the tendency of expanding hemispheres is rather to 
increase the breadth than the length. 
Turning now to the fundamental doctrine of phrenology, that 
different parts of the cerebral hemisphere are the organs of 
different mental faculties, we feel assured that no physiologist 
will hesitate in giving it a distinct and emphatic denial. It is 
true that the convolutions of the hemispheres are so constant 
that they are named ; but the existence of the convolutions is 
not for the sake of dividing the hemispheres into parts, and 
does not do so, but only affords, as has been said, facility for 
vascular supply ; and, at all events, the convolutions have not 
the smallest correspondence with the phrenological organs which 
cross them, cut them up, and combine them in the most regard- 
less fashion. 
But the fatal objection to the doctrine of different functions 
in different parts is to be found in the teachings of experiment 
and pathology. An animal will bear to have its cerebral hemi- 
spheres gradually sliced away; and the slicing may be done in 
any direction witli the same result, namely, gradually increas- 
ing stupidity, but witli no change of character according as one 
or other phrenological organ is removed. 
80 .also, persons have often recovered from wmunds from 
whicli portions of the brain liave protruded and been ampu- 
tate<l, but it makes no difference wdiat part of the hemisphere is 
injured ; nor, in cases of tumours destroying portions of the 
hemispheres, is it at all possible to state the position of the 
tumours from any alteration in the mental constitution of the 
