366 



D. OGATA AND SWALE VINCENT 



As is seen from the table, in 78.9 per cent the maximum re- 

 sponse is reached between twenty to forty per second stimula- 

 tion, and in one-third at the rate of forty per second. Beyond 

 these points the effect increased only in four cases. This phe- 

 nomenon may be seen a^so in figure 9. 



Kronecker and Nicolaides^o observed the fact that the effect 

 of stimulation of the vasomotor centers increased with the fre- 

 quency of stimuli up to twenty to thirty per second, but not 

 beyond this point. Tur^^ also pointed out that the effect of 

 stimulation of the lingual nerve increased until the stimuli 

 reached forty per second, beyond which, however, the effect 

 diminished. These observations coincide fairly well with our 

 own. 



5. EFFECTS UPON VASOMOTOR REFLEXES OF STIMULATING NERVE 

 TRUNKS OF DIFFERENT CATEGORIES (SENSORY, MOTOR, AND 

 MIXED NERVES) AND OF DIFFERENT SIZES 



According to the investigations of some authors, different 

 nerves, apart altogether from the depressor nerve, respond dif- 

 ferently to central stimulation. Hofmann,!^ in Nagel's Hand- 

 buch, says: ''There are single nerves, which for the most part 

 (glossopharyngeal) are depressor, and others which are exclu- 

 sively (splanchnic) or preponderatingly (sciatic, facial, infra- 

 orbital, cervical nerves) pressor." Vincent and Cameron studied 

 the effect of stimulating the main trunk of the sciatic, as well as 

 its common peroneal, lateral cutaneous, and purely muscular 

 branches, the saphenous, median of axilla, the hypoglossal, the 

 glossopharyngeal, the superior laryngeal, and the vagus. But 

 the different nerves all produced similar or comparable results 

 on the blood-pressure. They were strongly tempted to the 

 hypothesis that an equivalent stimulation of a roughly equal 

 number of afferent fibers will yield similar reflexes. 



