Freiburger historische Bestände – digital

22

Cunningham Memoirs.

congenital absence of the corpus callosum in a human brain. The
admirable drawing which he gives of the inner surface of the cerebrum I
have taken the liberty of reproducing (fig. 5). There is not a trace of the
calloso-marginal fissure, but, radiating from the fissura arcuata towards
the free border of the hemisphere, there are a number of divergent sulci.
These are undoubtedly to be regarded as the primitive, and usually
transitory fissures which are always present on the mesial face of the
hemisphere during the early stages of its development, and which in this
case have been preserved. Equally instructive are the figures given by
other authors of this face of the cerebral hemisphere in brains with no
corpus callosum. Those of Eichler,* Knox,f and more especially

Fig. 6.—Eeproduction of a figure by Onufrowicz, depicting a human brain in which
the corpus callosum was absent. FO., parieto-occipital fissure ; C, cal-
carine fissure.

Onufrowicz % (fig. 6), show the retention of the transitory fissural arrangement
in the most marked manner.

But it is not on the inner surface alone that the transitory fissures may
be retained. Hans Virchow§ has described and figured a very extraordinary
brain (fig. 7), in which the corpus callosum was absent in connexion
with hydrocephalus internus. The fissural type on both aspects of the

* Archiv f. Psychiatrie, vol. viii., pt. 2, 1878.

f Glasgow Medical Journal, 1885.

| Archiv f. Psychiatrie, vol. xviii., 1887.

§ " Ein Fall von angeborenem Hydrocephalus Internus, zugleich ein Beitrag zur Mikro-
cephalen Frage," v. Kolliker's Festschrift, 1887, Leipzig, p. 305.