852 THE SPINAL CORD. 



by the recurrence of this indistinct sensation of " tightness " she became 

 able to say when a "pain" was present. 1 Goltz 2 made observations on a bitch ; 

 * spinal transection was practised at the lower thoracic region ; six months 

 later " heat " came on, attended by the usual phenomena, psychical as well as 

 physical. Impregnation was effected, the animal became gravid. The 

 pregnancy was normal ; the mammary glands enlarged as usual. Parturition 

 followed in due course. Goltz and Ewald 3 have more recently observed 

 in a bitch, whose spinal cord from the lower thoracic region backward they 

 had exsected eight months previously, pregnancy follow coitus and terminate 

 with successful parturition. The animal suckled the puppies normally. The 

 mammary glands thus share in the pregnant and lying-in states when there 

 can be no spinal communication between the pelvic organs and the breast. In 

 the case of the patient reported by Routb, 4 it was so, although the destruction 

 of the cord in the region of the seventh thoracic nerve was, as confirmed by 

 autopsy, complete. The breasts enlarged during the pregnancy, and during 

 the puerperium the mammary function was performed with normal punctuality 

 and persistence. The quality of the milk was good. The relation of parturi- 

 tion to the spinal cord is probably more intimate in the second stage than the 

 first. The communication is with the lumbar region through the three most 

 anterior lumbar sympathetic ganglia. Connection of the lumbar region of 

 the cord with the brain is evidently not essential for the co-ordination of 

 uterine reactions, and even the lumbar " centre " can be altogether dispensed 

 with. More than one observer has, however, noted that section of the lower 

 part of the cord, made late in pregnancy or during labour, arrests labour. 



Eckhard 5 found the secretion of milk from the udder of the goat un- 

 influenced in quantity or quality by section of all the nerves of the organ. 

 The influence of the spinal reactions on the mammary secretion remains 

 unknown ; but that the secretion can be influenced through the cord, is 

 indicated by clinical observations which connect disturbance of the mammary 

 secretion with strong emotions, perhaps mediately through vasomotor 

 action. A prolonged contraction of the muscular and erectile tissue of the 

 nipple and areola, elicitable by firm compression of the nipple and areola, has 

 been described as "nipple reflex," 6 but it has yet to be shown that the 

 mechanical stimulus does not act by direct excitation of the contractile tissues 

 involved. In the rhesus monkey I have seen menstruation come on and recur 

 regularly after spinal transection at the twelfth thoracic level. 



Erection and seminal ejaculation. — Among the very few reflexes which, 

 after total transverse lesion of the cord, are in man preserved even from 

 immediately after incidence of the injury onward, are the sexual reflexes 

 of erection and seminal ejaculation. They occur especially in young adults. 

 Erection is evoked, not only by touching the genital surfaces, but also by 

 pressure on the bladder, or scrotum, or the perineal and anal skin, and from 

 the front of the thigh. 7 Ejaculation is much less usual than erection. 

 Priapism is of usual occurrence, and probably explicable simply by the 

 vasomotor paralysis. 



In the spinal mammal erection can be reflexly elicited. In the dog, after 

 spinal transection above the lumbar region, movements due to the skeletal 

 musculature are easily excited from certain genital regions. Touching the 

 preputial skin evokes bilateral extension at the knees and ankles, and to a 

 less extent at the hip-joints ; accompanying this there is depression of the tail. 



1 See A. Routh, Trans. Obst. Soc. London, 1897. 



- Jrch.f. d. gcs. Physiol., Bonn, 1874, Bd. ix. S. 552. 



3 Ibid., 1896, Bd. lxiii. S. 362. * Loc. tit. 



5 Beitr. z. Anat. n. Physiol. {Eckhard), Giessen, 1855, Bd. i. S. 12 ; 1877. Bd. viii. S. 

 117. Rbhrig believed slight reflex effects could be observed. Virchow's ArcUv, 1876, Bd. 

 lxvii. 



6 J. B. TIellier, Brit. Med. Journ., London, November 7, 1896. 



7 T. Kocher, Mitt. a. d. Qremtgeb. d. Med. u. Chir., Jena, 1896 Bd. i. S. 556. 



