The Journal of Comparative Neurology Volume 3 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1893 edition. Excerpt: ...arise in two different ways: (a) it may be formed by the ramus horizontalis of the inferior praecentral sulcus divorced from the vertical stem and assuming a very oblique or an almost vertical position: (l) It may consist of a new element placed between the superior and inferior praecentral furrows, but showing a closer connection with the former." "12. The superior frontal gyrus and the middle frontal gyrus are each partially subdivided into two tiers or subdivisions by furrows which may be respectively termed the sulcus frontalis mesialis and the sulcus frontalis medius. 13. Both of these furrows have secured a firm footing in the human brain, but only one (viz., the frontalis medius) has established itself upon the brain of the chimpanzee." "17. The sulcus frontalis mesialis is absent or poorly developed in the brain of the negro." "20. The sulcus prsecentralis inferior and the inferior frontal sul cus are the furrows which are most firmly impressed upon the brain of the apes. In Cebus they alone are present; in Calithrix there are also traces of the sulcus praecentralis superior and sulcus fronto-orbitalis; in the baboon there are, in addition, a rudimentary sulcus frontalis superior, and perhaps (?) traces of a sulcus frontalis medius. 21. In the chimpanzee and the gorilla the sulcus frontalis medius is often present in a form precisely similar to that seen in the human brain; in the orang the condition of this sulcus is doubtful; in the gibbon the sulcus frontalis medius is absent. 22. In the chimpanzee, therefore, the same convolution tiers may be seen as in man with this exception: the superior frontalis is never split into two by a sulcus frontalis mesialis. 23. The inferior frontal convolution of apes is very different from that in man....