xMUSCULAR SYSTEM. 129 



turn is a thin, cellular, fibrous expansion ; and, underneath this, 

 a layer of fleshy substance, which has, when contrasted with the 

 surrounding white parts, a remarkably red aspect. This is the 

 cremaster. Superiorly, at the internal ring, it has a tendinous 

 origin from the internal oblique and transverse muscles; from 

 which its fibres pass obliquely backward upon the chord, become 

 reflected along with it through the external ring, and terminate, 

 slantwise, in a digitated margin, just before the chord joins the 

 testicle. From its digitations, several slender flattened tendons 

 descend and expand upon the inferior surface of the tunica vagi- 

 nalis, with the substance of which they become so interlaced and 

 intermixed, that all further trace of them becomes lost. 



Action. — To retract the testicle (it has the power of withdraw- 

 ing it as high as the abdominal ring), and to aid in its suspension. 



ERECTOR PENIS. — Ischio-sub-peniaUs. 



Situation. — Upon the ramus ischii, and crus of the corpus 

 cavernosura. 



Figure. — Short, thick, conoid. 



Attachment. — Inferiorly, to the inner side of the infero-posterior 

 part of the tuberosity of the ischium ; superiorly, to the crus penis, 

 enveloping a considerable portion of it. 



Relations. — On the outer side, with the flexors of the thigh ; 

 on the inner side, with the accelerator urinae : internally, with 

 the corpus cavernosum. 



Direction. — Oblique ; from above, downwards ; and from with- 

 out, inwards. 



Structure. — Tendinous and fleshy at its ischial attachments ; 

 fleshy in other parts, excepting that its surfaces are in part apo- 

 neurotic. 



Action. — To promote the influx of blood into the penis at the 

 time of erection, by elevating and protruding the organ, and to 

 aid in retaining it ip the state of erection. 



TRIANGULARIS PENIS. — Ischio-urethralis. 



Situation. — Across the floor of the cavity of the pelvis, in front 

 of the ischial arch. 



Figure.— Thm and expanded. 



Attachment. — On either side, to the ischial portion of the os 

 innominatum ; in the middle, to the prostate gland. 



Relations. — Inferiorly, with the ischium and pubes ; superiorly, 

 with the prostates, membranous part of the urethra, and bladder. 



Structure. — It consists of a broad expansion of pale fleshy 



