MEDULLA OBLONGATA. 627 



the sexual appetite, and in others, its extensive degeneration or destruction 

 has apparently produced atrophy of the generative organs and total loss of 

 sexual desire. Serres reported several cases in which irritation of the cere- 

 bellum was followed by satyriasis or nymphomania, but in other cases there 

 were no symptoms referable to the generative organs. In the well known 

 case reported by Combette, the patient had the habit of masturbation. 

 Fisher, of Boston, reported (1838) two cases of diseased or atrophied cere- 

 bellum, with absence of sexual desire, and one case of irritation, with saty- 

 riasis. Similar instances have been given by other writers. The observa- 

 tions of Budge, in which mechanical irritation of the cerebellum was followed 

 by movements of the uterus, testicles etc., have not been satisfactorily ex- 

 plained. 



Although there are many facts in pathology which are opposed to the 

 view that the cerebellum presides over the generative function, there are 

 cases which show a certain connection between this portion of the central 

 nervous system and the organs of generation in the human subject ; but this 

 is all that can be said upon this point. It is certain that the facts are not 

 sufficiently definite and invariable to sustain the notion that the cerebellum 

 is the seat of the sexual instinct. 



It is not necessary to discuss the vague theories with regard to the uses 

 of the cerebellum advanced by writers anterior to the publication of the ob- 

 servations of Flourens. There is no evidence that the cerebellum is the 

 organ presiding over memory, the involuntary movements, general sensibility 

 or the general voluntary movements. The only view that has any positive 

 experimental or pathological basis is that it presides over equilibration and the 

 co-ordination of certain muscular movements, and is, perhaps, in some way 

 connected with the generative function. 



MEDULLA OBLONGATA (BULB). 



The medulla oblongata, or bulb, connects the spinal cord with the 

 encephalic ganglia. It is composed of white and gray matter and presents, 

 in its substance, a number of important nerve-centres. It is not necessary 

 to give anything like a complete anatomical description of the medulla. Its 

 most important conducting parts are those which are continuous with the 

 columns of the cord and which pass to the cerebrum and cerebellum. The 

 nuclei of origin of certain of the cranial nerves in the floor of the fourth ven- 

 tricle have already been mentioned. 



Physiological Anatomy. The medulla oblongata is pyramidal in form, 

 with its broad extremity above, and rests in the basil ar groove of the occipital 

 bone, extending from the lower border of the pons Varolii to the atlas. It 

 is about an inch and a quarter (31-8 mm.) in length, three-quarters of an 

 inch (19-1 mm.) broad at its widest portion and half an inch (12-7 mm.) 

 thick. It is flattened antero-posteriorly. Like the cord, it has an anterior 

 and a posterior median fissure. 



Apparently continuous with the anterior columns of the cord, are the 



