Cerebellum and brain-stem
Roswell P. Angier
Rothmann (13), in extirpation experiments on the cerebellum of the monkey, reports that excision of the cortex of the lobus quadrangularis causes disturbance in the movements of the fore-leg of the same side and that similar disturbances of the corresponding hind-leg appear on cortical excision of the lobus semilunaris superior. Further, if the lateral, median, upper or lower portions, respectively, of either lobe are affected there occur well defined and constant disturbances in leg movement.
... y simultaneous extirpation of such various portions, either on the same or on opposite sides, different combinations of these denned disturbances may, therefore, be brought about. To such results Rothmann gives the Sherringtonian interpretation-that the cerebellum is the central organ of the proprioceptive system in control of the skeletal muscular reflex tonus and that, consequently, when cerebellar disturbances occur reactions dependent on this system fall out-when, for example, the lateral part of the cerebellar fore-leg center is extirpated, there occurs an absence of the proprioceptive antagonistic reflexes of the adductor muscles, so that the leg may be displaced outwards without being reflexly withdrawn. Rothmann also believes that he has demonstrated that the center for the innervation of the muscles of the larynx is likewise in the cerebellum (lobulus centralis of the lobus anterior). The outlook for extending to the cerebellum and the rest of the nervous s'ystem the postulate of that finer localization now become dominant for the cerebral cortex is, according to him, decidedly bright. Brouwer (1) finds that the cerebella of birds show (as Bolk and others had demonstrated for mammals) a certain fundamental type of fissure formation, but he feels that the bird-cerebellum hardly supports the conception of a typical localization of function of the kind maintained by Bolk for mammals. But from the study of bird-cerebella he is much inclined to look on the cerebellum as the regulative organ for the proper coordination of a part of bilaterally functioning muscle-groups. Camis (4) studied the effects of injections of nicotine into the nuclei of the cerebellum. Ocular disturbances predominated when the injections occurred in a lateral lobe and general motor dis-1 For the last previous review on this topic see the BULLETIN, 1913, 10, 138-142.