( -m ) 



Nerve and the first braiicli of the N. trigemimis into it. If this 

 happens, one n.ay suddenly see the regular rhythm whicli existed 

 before quickened not only, but the acceleration of I'hythm may be 

 superimposed upon the existing rhythm (Fig. 6). 



Then a very typical tracing of resjiiration is obtained. Not always 

 the superposition of the quick rhythm takes place so completely, often 

 the acceleration covers the former type partially, and if the sighs, 

 nientioned before, interfere Avith the two rhythms of respiration des- 

 cribed, the tracing may become of an extreme irregularity. In such 

 cases it is impossible to experiment on the changes, which respira- 

 tion undergoes during the stimulation of the cortex. 



T/ie effect of (he excitation of bulbns, tractus and lohiis 

 olfactorius upon respiration. 



If the consequences of the narcosis and the operation are known, 

 and the tracings obtained in such abnormal conditions understood, 

 it may be possible to study tlie strange effects, which the excitation 

 of the bulbus, the tractus and the lobus olfactorius produces upon 

 respiration . 



MuNK, Danilewsky, ^) Unveuricut ") and others obtained expira- 

 tory effects on stimulating different parts, principally the basal parts 

 of the brain. Spekcer mentions the effects after stimulating the 

 lobus olfactorius in a most accurate manner. 



Our results differ in many points from the results reported by these 

 authors. In a single point our experiments agree with, and confirm 

 the view of Spekcer viz. with regard to the existence of a well 

 defined spot on the lobus olfactorius, stimulation of which produces 

 slowing of respiration and arrest of the respiration in expiration, 

 even if weak currents are used. 



In our diagram (Fig. 9) this point is indicated by tlie letters 

 /■ and (J. It is found on the lobus olfactorius, on the border of 

 the fissura rhinica, exactly behind the place where the fissura prae- 

 sylvia touches the fissura rhinica. 



But our experiments teach us more. The same effect may be 

 obtained from the tractus and also from the caudal end of the bulbus 

 olfactorius. However, we can state, that it can only be produced 

 from the basal surface of the olfactory bulb, and from the basal 



') Danilewskï. Experimentelle Beitriige zur Physiologic des Geliirus. Pflüüek's Arch, 

 f. Phys. Bd. XI. 1875. p. 128. 



^) Unverricht. Experimentelle Untersuchungen iiher die Innervation der Athmungs- 

 bewegungen. Verlumdlungen des Conoresses fur Innere Medicin. Wiesbaden 1888. 



