MALE ACCESSORY REPRODUCTIVE ORGANS ^57 



lation of the 5tli lumbar nerve had no effect upon the generative 

 organs, but the 1st lumbar was observed to have a distinct 

 action, and also the 13th and 12th thoracic. In the rabbit no 

 effect was produced by stimulating the 1st lunibar nerve. The 

 2nd lumbar had a shght action occasionally, but the 3rd, 4th, 

 and 5th lumbar nerves always had an effect which was more or 

 less pronounced. 



The fibres from the lumbar nerves run in the white rami 

 communicantes to the sympathetic chain, where they take two 

 routes, (a) The majority of the fibres take the course of the 

 pudic nerves (nervi pudendi). They follow the sympathetic 

 chain to the sacral gangha, from which fibres are given off, and 

 these run in the grey rami communicantes to the sacral nerves. 

 Their further course is by way of the pudic nerves (i.e. in the 

 somatic branches), none apparently running in the nervi erigentes 

 (i.e. to the visceral branches), (b) The second of the courses 

 taken by the lumbar nerve fibres is that by the pelvic plexus. 

 Only a relatively small number, however, take this route. 

 Most of them run in the hypogastric nerves, but a few may join 

 the plexus from the lower lumbar or upper sacral sympathetic 

 chain, or from the aortic plexus. Of these latter, some may 

 join the first root of the nervus erigens, and proceed with it to 

 the pelvic plexus.^ 



It has already been mentioned that the chtoris in the female, 

 like the penis, undergoes erection during coitus. The same is 

 the case with the other parts of the vulva which contain erectile- 

 tissue. The friction which is set up between these structures 

 and the glans of the penis causes a reflex discharge of motor 

 impulses in both the female and the male. In the female the 

 uterus undergoes a series of peristaltic contractions, by means 

 of which the semen is sucked into its cavity (see p. 180). More- 

 over, BarthoMni's glands show an increased activity and pour 

 out a viscid secretion. In the male, the sexual impulses cul- 

 minate in the emission of the semen. This is brought about 

 by a series of muscular contractions, which probably begin in 

 the walls of the vasa efferentia and pass to the canal of the 

 epididymis, and thence along the vas deferens on either side. 

 The vesiculse seminales contract simultaneously, expelling their 



' Langley and Anderson, loc. cit. 



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