500 ON THE BRAIN OF ATELES PANISCUS 
Bereiche des unteren Hornes des Seitenventrikels vorkommen, 
angewendet.” 
“ The eminentia lateralis, or collateralis, or Meckelii, is formed by 
a rounded elevation which lies in front of the entrance into the 
posterior, and beside that into the inferior cornu of the lateral 
ventricle, and is situated external to the cornu Ammonis.” 
It will be observed that Valentin, who has taken great care to 
collect together the multitudinous synonyms of the parts of the 
brain, does not enumerate “ pes hippocampi minoris” among those of 
the eminentia collateralis; nor has the term ‘pes hippocampi 
minoris’ been ever used in this sense by any anthropotomist of 
authority. 
And if it be an error in terminology to apply the name of pes 
‘hippocampi minorzs’ to the eminentia collateralis, it is a still greater 
error, in point of anatomical fact, to assert that “the eminence 
continued backwards from the pes into the posterior cornu is the 
hippocampus minor.”! If any eminence is continued backwards from 
the eminentia collateralis into the posterior cornu (as sometimes 
happens) it lies in the floor of the cornu, alongside the hippocampus 
minor, but perfectly distinct from it. But it will perhaps be better to 
demonstrate this elementary fact over again, though IJ feel that the 
doing so necessitates an apology to those who are conversant with the 
anatomy of the human brain.? 
The lower figure of the woodcut (fig. 2) represents the inner 
surface of one of the hemispheres of the human brain. The contour 
is taken from one of Foville’s Plates, but only the principal sulci are 
indicated,—those marked 4, #, and x being put in from a specimen 
which I dissected, so as to ascertain their true nature. Of these sulci, 
that marked 77 is the sulcus called by Gratiolet ‘ fronto-parietal,’ a 
name which involves an ambiguity, and for which I therefore propose 
to substitute ‘ calloso-marginal,’ as this sulcus lies between the corpus 
callosum and the margin of the hemisphere ; “# is the occipito-parietal 
sulcus (scissure perpendiculaire interne, Gratzolet) ; 7 is the posterior 
part of the “scissure des hippocampes” of Gratiolet. This sulcus is 
a very remarkable one. Commencing just in front of the posterior 
thickening of the corpus callosum, opposite +, it rapidly deepens as it 
1 Prof. Owen, Athenzeum, March 23rd, 1861. 
* Compare, for example, the well-known standard English ‘Elements of Anatomy,’ by 
(Juain and Sharpey, where the relations of the eminentia collateralis and hippocampus minor 
to distinct convolutions are clearly pointed out (p. 710). Malacarne (Encefalotomia Nuova, 
1780, part ii. p. 67) describes the continuation of the eminentia collateralis forwards into the 
descending cornu under the fanciful name of ‘‘Gamberuolo,” or greave. It appears to be 
more constantly of large size than the continuation backward into the posterior cornu. 
