THE CORTICAL THERMIC CENTER. 7QI 



of a point in the third primitive convolution external to the center for the 

 orbicularis of the eyelids. Preobraschensky observed inspiratory spasm of the 

 diaphragm in the cat after irritation of a point behind this center. The increased 

 secretion of saliva observed by Landois has been referred to on page 262. 



According to v. Bechterew and Ostankow a point irritation of which causes 

 swallowing movements is situated externally to the cruciate sulcus. Bochefon- 

 taine and L6pine observed further, particularly after irritation in the neighbor- 

 hood of the cruciate sulcus in dogs, slowing of the movements of the stomach, 

 peristalsis of the intestines, contraction of the spleen, the uterus, and the bladder, 

 and increased respiratory frequency. Bufalini observed the occurrence of secre- 

 tion of the gastric juice with elevation of the temperature in the stomach after 

 irritation of the same cortical area whose irritation in rabbits caused movements 

 of the jaw. The relations of the region about the cruciate sulcus in the dog to 

 the cardia are considered on page 281. According to Bechterew and Mislawski 

 irritation of various points in this region causes in part movements at the pylorus, 

 and in part inhibition of such movements; occasionally the cardia is set in motion. 

 From the same point and from the third primitive convolution situated poste- 

 riorly and externally contraction and relaxation of the muscles of the perineum can 

 be induced, and also from the optic thalami. The conducting paths are contained 

 in part in the vagi, in part in the spinal cord. From the latter the fibers for the 

 small intestine pass through the eight lower dorsal and the uppermost lumbar 

 nerves in the dog to the sympathetic plexus, those for the large intestine through 

 the last two lumbar and the upper three sacral nerves. The foregoing statements 

 afford an explanation of the fact that in epileptic attacks induced by irritation 

 of the cortex contraction of the stomach, the intestine, and the bladder have also 

 been observed. 



Electrical stimulation of the inner portion of the sigmoid gyrus in the dog 

 causes dilatation of the pupils (as does also chemical irritation of the parietal 

 region in the rabbit) ; secretion of tears, protrusion of the eyeballs, and 

 retraction of the third eyelid in the dog. Increased contractions of the vagina 

 in rabbits could be induced by irritation of the anterior portion of the hemisphere, 

 in dogs by irritation of the sigmoid gyrus. By irritation in the neighborhood, 

 or by increased irritation, an inhibitory effect could be induced. Irritation of 

 the optic thalamus or of the central stump of the vagus likewise gave rise to in- 

 crease in the movements, while irritation of the peripheral stump of the vagus 

 caused relaxation of the vagina. 



Attention should finally be directed to a number of observations of pathological 

 significance made after injuries to the brain. Thus, Schiff, Ebstein, Klosterhalfen, 

 and v. Preuschen observed, after injuries to the pons, the striate body, the optic 

 thalamus, the cerebral peduncle, the quadri geminate bodies, the middle cere- 

 bellar peduncle, and the medulla oblongata, often hyperemia and extravasations of 

 blood into the lungs, the pleurae, the stomach, the intestines, and the kidneys. 

 In this manner is to be explained the occurrence of hemorrhage into the stomach 

 in new-born infants with injury to brain (melasna neonatorum) ; perhaps also the 

 occurrence of gastric ulcer in adults in association with cerebral disease, v. Preu- 

 schen observed gastric and intestinal hemorrhage in rabbits also after injury of 

 the cornu Ammonis, the floor of the anterior horn, the frontal lobe, and the upper 

 portion of the spinal cord. Analogous phenomena have been observed in man 

 after cerebral hemorrhage or softening. Brown-Sequard and Nothnagel induced 

 hemorrhage into the lungs by irritation of basal portions or of a point on the 

 surface of the brain. 



The cerebral unilateral acute decubitus described by Charcot is particularly 

 noteworthy, occurring always upon the paralyzed side, therefore on that opposite 

 to the cerebral focal lesion. It may begin as early as the second or the third day 

 and rapidly progress to a fatal termination, with profound destruction (but- 

 tock, lower extremity). The decubitus that appears in connection with disease 

 of the spinal cord generally begins in the middle line of the buttocks and spreads 

 thence symmetrically toward either side. In cases of injury of one side of the 

 spinal cord this destruction takes place on the corresponding side of the sacrum. 



PHYSIOLOGICAL TOPOGRAPHY OF THE SURFACE OF THE 

 CEREBRUM IN MAN. 



In the brain of man the physiologically analogous systems of fibers receive 

 medullary sheaths approximately at the same time, the olfactory tract among 



