442 THE TESTICLES AND ACCESSOEY STRUCTUEES. 



of the scrotum than behind, and, moreover, it forms two distinct sacs, 

 which contain the corresponding testes, and are united together along 

 the middle line so as to establish a median partition between the two 

 glands named the septum scroti, which is adherent below to the deep 

 surface of the raphe, and reaches upwards to the root of the penis. 

 The dartos is ...very vascular, and, as was first shown by Kolliker, 

 owes its contractile properties to the presence of a considerable amount 

 of unstriped muscular tissue. Its contractility is slow in its action ; 

 it is excited by the application of cold and of mechanical stimuli, but, 

 apparently, not by electricity. By its general contraction the skin of 

 the scrotum is drawn together and more or less corrugated. 



3. The inter columnar or spermatic fascia, a very thin and trans- 

 parent but relatively firm layer, derived from the tendon of the external 

 oblique muscle of the abdomen, is attached above to the margins of the 

 external ring, and is prolonged downwards upon the cord and testicle. 

 It lies at first beneath the superficial fascia, and lower down beneath 

 the dartos, and it is intimately connected with the layer next men- 

 tioned. 



4. The cremasteric layer is composed of scattered bundles of striped 

 muscular fibres, connected together into a continuous covering by inter- 

 mediate areolar membrane. The red muscular portion, which is con- 

 tinuous with the lower border of the internal oblique muscle of the 

 abdomen, constitutes the cremaster muscle, and the entire covering is 

 named the cremasferk fascici. By the action of the cremaster the cord 

 is shortened and the testicle is raised towards the body. 



5. The infundibuliform fascia, continuous above with the fascia 

 transversalis and the subperitoneal areolar membrane, and situated 

 immediately beneath the cremasteric fascia, invests the cord com- 

 pletel}^ and is connected below with the posterior part of the testicle 

 and the outer surface of its serous tunic. On forcing air beneath the 

 infundibuliform fascia, a quantity of loose and delicate areolar tissue 

 is seen to connect its deep surface with the vas deferens and spermatic 

 blood-vessels, and to form lamella between them. This areolar tissue 

 is continuous above with the subserous areolar tissue found beneath the 

 peritoneum on the anterior wall of the abdomen ; below, it is lost upon 

 the back of the testicle. Together Avith the infundibuliform fascia, it 

 forms the fascia projma of A. Cooper. 



Lying amongst this loose areolar tissue, in front of the upper end of 

 the cord, there is often seen a fibro-areolar band, which is connected 

 above with the pouch of peritoneum found opposite the upper end of 

 the inguinal canal, and which passes downwards for a longer or shorter 

 distance along the spermatic cord. Occasionally it may be followed as 

 a fine cord, as far as the upper end of the tunica vaginalis ; sometimes 

 no trace of it can be detected. It is the vestige of a tubular process of 

 the peritoneum, which in the foetus connects the tunica vaginalis with 

 the general peritoneal membrane. The testicle is placed within the 

 abdomen during the greater part of foetal life ; but at a period con- 

 siderably prior to its escape from the abdominal cavity, a pouch of 

 peritoneum already extends down into the scrotum. Into this pouch, or 

 processus vaginalis inritomd, the testicle projects from behind, sup- 

 ported by a duphcature of the serous membrane, named the mesor- 

 cliium. Sooner or later after the gland has descended into the scrotum, 

 the upper part or neck of this pouch becomes contracted and finally 



