1010 DU. C. b\ SONNTAG ON THE PELVIC MUSCLES 



]i. The internal generative organs in Man difl'er from those in 

 the Chimpanzee in the following respects : — 



1. The testis is relatively smaller and the corpus Highmori- 

 anum is smaller. The epididymis has a different form. 



2. The vesiculiB seminales consist of a short tubular and a 

 large glandular part, whereas the reverse is the case in the 

 Chimpanzee. Moreovei", according to Milne-Edwards, the 

 Chimpanzee has the same characters as the Orang. 



3. Cowper's glands are relatively smaller. 



C. Man and the Chimpanzee agree in the closure of the com- 

 munication which originally existed between the tunica vaginalis 

 and the peritoneal cavity. In the Orang and Gibbon this remains 

 open. 



1). The urethra is ante-prostatic in the Chimpanzee and Orang, 

 whereas it descends through the prostate in Man. 



E. The orifices of the ejaculatory ducts are close together in the 

 Chimpanzee, and they appear rounded. In Man they are sepa- 

 rated slits. In Mandrillus (10) there is a common orifice for the 

 two ducts. Milne-Edwards (6) points out that the arrangement 

 in the Orang is as described above in the Chimpanzee. 



F. The spermatozoa of the Chimpanzee do not resemble those 

 of Man, but those of the Gorilla do according to Retzius (8). 



G. The interior of the bladder and rectum is as in the female 

 already described by me (9). 



H. The muscles of the perineum and pelvic fioor are built on 

 the same plan as in Man, but the Chimpanzee has a retractor ani 

 and no transverse perineal muscles are present. The ischial spine 

 varies, so there are slight modifications in the origin of the 

 levator ani. 



It is, therefore, evident that Man difi'ers in many ways from 

 the Chimpanzee and Orang in the characters of the male repro- 

 ductive organs. He agrees with the Gorilla in the presence of a 

 glans penis, the characters of the vesiculai seminales, and in his 

 spermatozoa. 



Bibliography. 



1. DuvERNOY, G. L. — " Las Caract6res anatomiques des grands 



Singes." Arch. Mus. Hist. Nat. Paris, 1855-5G, pp. 1-248. 



2. Keith, A. — " An Introduction to the Study of the Anthro- 



poid Apes." Natural Science, vol. ix., 18i)6. 



3. KojiLURuaQE, J. 11. F. — " Versuch einor Anatomie des Genus 



Hylobates.'" Max Weber's Zool. Ergebnisse einer Reise in 

 Niederland, etc. 1890. 



4. LAiirscHNEiDER, J. — " Die Steissbeinmuskeln des Menschen 



. und ihre Beziehungen zum M. levator ani und zur Becken- 

 fascie." Denkschr. K. Ak. Wiss. Wien, 1 895, pp. 95-1 30. 



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