( 136 ) 



tonyiie when the .suooiulary coil was 1 1 cM. from euveriug the 

 primary. 



A Desprez-signal indicates the moment of stimuhition on the 

 cylinder, wliile the respiration is registered with the pneumograph 

 of Marey and the arteria femoralis with an instrument borrowed 

 from the tonometer of Talma. 



At eight o'clock in the morning the dog gets from 30 — 50 mi^v. 

 morphia, depending on its size. In narcose with ether the frontal 

 lobe is exposed as far as the dura mater, according to the well- 

 known method. 



After a long time of rest and when the respiration is no longer 

 disturbed by the morphia, the experiment begins about one or two 

 in the afternoon. 



The surface of the brain, representations of which will be found 

 in fig. XXI — XXIV, is divided into a number of squares, so far 

 as it is required for our purpose. The size of these squares are 

 determined by the topography of the cortex. 



After having determined the different centres on the cortex by 

 stimulating a well-known area of the motor region, the animal 

 breathing calmly, it is first found, that there are a number of centres 

 from which it is impossible to bring about any change whatever in 

 the respiration. 



It appears however, that constant changes may be brought about 

 regularly after stimulation of a few points indicated by 15 and 16 

 in the scheme. This point lies in the transition from the gyrus 

 sigmoideus (prae-cruciatus) to the frontal lobe and in the second 

 lateral gyrus near the place, where the fissura coronalis approaches 

 the fissura praesylvia closely. As soon as we stimulate with an 

 exceedingly weak current e.g. with 11 cM. distance between the 

 coils, some quick inspirations are seen to be brought about as in 

 fig. XXIY. If we stimulate with a current somewhat stronger, the 

 inspiration becomes somewhat quicker and is accompanied by acce- 

 leration of pulsation (see fig. XXV). A moderately strong stimulation, 

 e.g. of cM. distance, causes a stronger spasm of inspiratiou with 

 strong acceleration of pulsation, whereas the current also irradiates, 

 and causes stretch-movements of the muscles of arm and neck (see 

 fig. XXVIj, which were distinctly visible, so that it was unneces- 

 sary to register them. In fact the respiration (inspiration) centre 

 mentioned, lies between the centre for stretching the muscles of the 

 hand and that for lifting the neck. 



This acceleration of respiration with deeper inspirations, eventually 

 restraining and shortening of the expiration is always followed by 



