. Text book of vertebrate zoology. Vertebrates; Anatomy, Comparative. 52 MORPHOLOGY OF THE ORGANS OF VERTEBRATES. (educabilia) fissures appear in its surface, separating convolu- tions or gyri, and the higher the mammal the more numerous the convolutions. It will readily be seen that this produces an increase in surface, and consequently of cortical (ganglionic) substance ; and it is noteworthy that this increase is correlated with increase of intelligence. From its anterior ventral region each hemisphere gives off an olfactory lobe (rhinencephalon) into which a part of the ven- tricle may ext - Stock Image