Scientific Proceedings. 



83 



Examination of the curve shows that over the period of the 

 fast there was a gradual diminution of the opsonic power till 

 finally at the end of the fast, on the ninth day, it was 0.7. 



We do not lay stress upon the small differences shown 

 between some of the successive observations but we consider that 

 the difference between 0.98 and 0.7 is absolutely definite. 



We would call attention to the steady rise to and retention at 

 the normal after the fast was broken. 



We fully realize that a sweeping statement regarding the 

 variations in the resistance of the body cannot be made from our 

 observations on the opsonic power against staphylococcus aureus ; 

 nevertheless, it is of interest that a decided fall in the power did 

 occur against this organism. Moreover, if we take it that the nat- 

 ural opsonins which exist in the body are general and not specific, 

 it would not seem unlikely that the phagocytic index against 

 other organisms could be shown to be diminished correspondingly. 



56 (199) 



The automatism of the respiratory center. 

 By 6. N. STEWART and F. H. PIKE. 



[From the Hull Physiological Laboratory, University of Chicago^ 



In the course of observations on the resuscitation of the central 

 nervous system we have had the opportunity to determine whether 

 regular, spontaneous respiratory movements can be discharged at 

 a stage in the resuscitation when as yet the respiratory center is 

 unaffected by stimulation of afferent nerves. The respiratory 

 movements, and usually the arterial blood pressure as well, were 

 recorded and the effect of stimulation of the central ends of the 

 vagus, brachial plexus and sometimes the sciatic determined before 

 occlusion of the arteries supplying the brain, the bulb and the upper 

 portion of the cervical spinal cord. These arteries (innominate and 

 left subclavian proximal to the origin of the left vertebral) were 

 then occluded by temporary ligatures. At intervals during the 

 occlusion and again after releasing the vessels the nerves were 

 stimulated, of course with the same strength of stimulus as before. 

 Artificial respiration was kept up from the time when natural res- 



