Volume 1

On the anatomy, physiology, and pathology of the chimpanzee / by Charles F. Sonntag.

  • Sonntag, Charles F. (Charles Frederick), -1925.
Date:
1923
Catalogue details

Licence: In copyright

Credit: On the anatomy, physiology, and pathology of the chimpanzee / by Charles F. Sonntag. Source: Wellcome Collection.

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    of the same toe. The third is placed more superficially than the others, and lies in the same plane as the opponens minimi digiti. Its belly crosses the fourth space from its origin on the external long plantar metatarsal ligament, and the ligaments over the base of the fourth metatarsal to its insertion on the inner side of the fifth toe. The dorsal interossei are inserted more into the proximal phalanx than into the dorsal expansion, but the plantar inter- ossei exhibit the reverse. The important points to be noted from the physiological point of view are :—1. The middle line of the foot runs through the middle toe instead of through the second, as in Man. So the interossei of the foot of the Chimpanzee act as they do in a hand. 2. There are no additional plantar interossei in the foot as there are in the hand. The disposition of the muscles in four layers in the sole of the foot is as in Man. The nature of the terminal part of the pelvic extremity is described on page 423. Muscles of the Pelvis. Levator AniIn this animal the levator ani consisted of the same parts as described by Lartschneider (32). The iliac portion arose from the margin of pelvis minor, and the pubic portion arose from the back of the symphysis pubis. It is inserted into the sides of the lower end of the rectum and the ano-coccygeal raphe. The ischio-coccygeus is a small muscle running from the side of the coccygeal vertebrae to the inner aspect of the back part of the ischial tuberosity. Lartschneider has described a pelvic diaphragm in a female Chimpanzee. The perineal muscles differ from those in the human condition. The vulva and anus are very close together, so there is no true central point of the perineum, nor is there a trace of transverse perineal muscles. The 'ischio cavernosi have long origins from the ascending pubic rami ; they run over the crura clitoridis, and the opposite muscles are blended. The sphincter vagince is a strong collar surrounding the upper part of the vagina and extending backwards on to the rectum. It has a narrow anterior slip which fuses with the meeting point of the two ischio- cavernosi. The sphincter ani externus blends in front with the sphincter vaginae, and it is attached behind to the ano-coccygeal raphe, which is very powerful. The ischio-rectal fossae are well marked and laden with fat. No well-marked bursa exists over the ischial tuberosities. And the fascia is not divided as in Man into a superficial fatty layer and a deep fascia of Colles. The orbital muscles are described on page 415, and the laryn- geal muscles on page 398. [41]