676 ANATOMY OF VERTEBRATES. 



is connected to the symphysis pubis by means of a strong tri- 

 angular fascia, the * ligamentum suspensorium penis.' 



The ( corpus cavernosum ' is composed of a cellular structure 

 enclosed in a strong sclerous tunic, from the inner surface of 

 which are given off numerous bands, ' trabeculrc,' which converge 

 towards the middle line of the inferior wall ; they are most 

 abundant in the middle line of the organ, where they form a 

 septum between the two lateral halves of the corpus cavernosum: 

 but this becomes incomplete or f pectinate ' anteriorly. The 

 so-called cellular structure of the corpus cavernosum consists of a 

 plexus of dilated and freely intercommunicating veins, the inter- 

 spaces of which are occupied by contractile tissue : the fibres 

 being unstriped and with a general arrangement transversely to 

 the axis of the penis. 



Besides the ( erectores penis ' and ( acceleratores urinse,' there is 

 a remnant of the ' levatores penis ' reduced to the function of 

 fc compressors venre dorsalis;' and occasionally a small fan-shaped 

 muscle, ' ischio-bulbosus,' may be defined in the interspace 

 between the bulb and crura penis, having a slender attachment 

 to each ischium, and expanding upon the bulb. The prepuce 

 is connected to the glans on its under part by means of a narrow 

 fold, with some sclerous tissue, termed the ( fraenum praeputii.' 

 At the base of the prepuce, where it is reflected over the glans, 

 open the small lenticular representatives, called ( glandules 

 odoriferas,' of the preputial follicles of lower Mammals. 



B. FEMALE ORGANS OF MAMMALS. 



The ovaries retain, as in lower Vertebrates, their abdominal po- 

 sition; but are relatively small in Mam- 

 malia, and consist of a dense areolar 

 ' stroma,' which, with the ovisacs therein 



J * 



developed, is inclosed in a firm sclerous 

 ' tunica albuoiinea,' fio-. 534, a. The 



o ^ O * 



abdominal aperture of the oviduct is 

 wide, and, as a rule, ' fimbriate ;' but 

 the canal quickly contracts, usually to 

 a diameter like that of the spermduct, 

 and, after a certain course, suddenly 



Section of Human Ovarium ; nat. size. expands, Or OpCUS, llltO a ' UterUS.' TlllS 



may remain distinct from its fellow ; 



but a prevalent mammalian characteristic is a blending of the 

 uteri, to terminate by one valvular orifice in a ( vagina;' the con- 

 fluence extending, by degrees, in different species, until a single 

 uterus results. The vagina, as a rule, is single, and usually 



