Most physiologists, however, readily admit that the functions of this large and complicated organ are still very obscure. Dr. Courmont's book is assuredly the most systematic attempt yet made to throw light into the darkness. He believes that the evidence points to a distinct psychic function for the cerebellum. As the cerebral hemispheres are the organs of the intellectual processes, so the cerebellum, according to him, is the organ of the feelings, sentiments, and emotions.
This rather startling thesis is defended at great length, but in so clear and well-ordered a way that the book can be easily and rapidly read. After three chapters, abounding (like all the chapters of the book), with quotations from the most accredited authors, and destined to prove the chaotic character of opinion about the cerebellum, the author begins the methodical array of his own proofs, as follows:
1. The histology of the cerebellum is analogous to that of the cerebrum, and their anatomical union is extremely intimate.
2 and 3. The cerebellum receives important contributions from the posterior or sensitive columns of the spinal cord; and the clinical reports which are supposed to prove that cerebellar-lesions do not affect the 'mind,' are either full of omissions or do contain references to emotional disorder, either of defect or excess. These facts warrant the presumption that the cerebellum has psychic functions of some kind.
4. The vivisections of Vulpian and Ferrier show that animals still give signs of pain after the hemispheres are removed. Now the cerebellum is as likely to be the source of this pain, as the pons or medulla, one or other of which is usually held responsible for it.
5. The record of clinical observations where the cerebellum alone has been found diseased shows unmistakably the connection between this organ and the emotional life. Where the disease is irritative, e.g. in cases of tubercles, tumors, or sclerosis, abscess, etc., we may find hypochondria, melancholy, irascibility, and especially terror. Sometimes these symptoms alternate with hilarity. Loud cries are a very frequent symptom; and though in many cases they are due to intense pain in the head, in other cases they occur where there is no concomitant pain. The peculiar expression of pain or anxiety in the face is often noted. The emotional symptoms, as well as the cries, are apt to appear paroxysmally. Where, on the contrary, the lesion is destructive, a profound indifference or apathy is noted, even with intelligence preserved. [The lesions in many of Dr. Courmont's quoted cases are not clearly distinguishable as irritative or destructive. — W. J.] Lesions of the pons (which anatomically is essentially the commissure of the two cerebellar halves) show the same results as lesions of the cerebellum itself.
6. In woman, in whom, as compared with man, the emotional life
