200 
ME. W. H. ELOWEE ON THE POSTEEIOE LOBES 
Explanation of the Plates. 
PLATE II. 
All the figures are of the natural size, except the first. 
Fig. 1. Inner face of the right cerebral hemisphere of human brain, reduced one-half in 
linear dimensions. A, B, C. Sections of the posterior lobe at the points 
indicated by the lines so lettered. 
Fig. 2. The same part of Presbytes leucoprymnus. 
Fig. 3. The same part of Cercopithecus pygerythrus. 
Fig. 4. The same part of Macacm erythrceus. 
PLATE III. 
Fig. 5. The same part of Cehus apella. 
Fig. 5 a. Horizontal section of left hemisphere of Preshytes leucoprymnus. The trans- 
verse lines show the mode of estimating the length of the posterior portion 
of the brain (B) as compared with the antero-median (A). 
Fig. 6. Side view of the brain of Cercopithecus pygerythrus, showing the exact form 
when in situ. The outline is drawn from a cast of the interior of the cranium. 
Fig. 7. Horizontal section of the brain of the same animal. On the right side the 
middle and posterior cornua are completely opened, so as to exhibit the rela- 
tive size and situation of the two hippocampi. In exposing the hippocampus 
minor to this extent, the limits of the cornu (as seen in the sections A, B, C, 
fig. 3) have not been exceeded; but as the walls are more or less adherent, 
this must be regarded partly as a dissection. On the left side the walls of 
the cornu remain undisturbed, part of the brain only having been cut away 
to expose the commencement of the hippocampus major. 
Fig. 8. Side view of the brain of Hapale jacchus. 
Fig. 9. Upper surface of the same brain, the left hemisphere in section. 
Fig. 10. Inner face of the right hemisphere of the same brain. B. Section of the 
posterior lobe. 
Fig. 11. Upper surface of the brain of Lemur nigrifrons. 
Fig. 12. Base of the same brain. 
Fig. 13. Side view of the same. 
Fig. 14. Inner face of the same. B. Section of the posterior lobe. 
Fig. 15. Horizontal section of the brain of Galago. On the right side the section is 
carried rather low, and the hippocampus minor cut through ; on the left the 
whole surface of this structure is exposed by opening the posterior cornu 
from above. The form of the brain is somewhat altered by keeping in 
spirit. 
