144 Fractional Activity in Mammalian Reflex Phenomena. 



Experiment, 28.10.12 (No. 6 in table). Low spinal cat, cord divided at 

 11 A.M. A record similar to that reproduced in fig. 1, save that the series is 

 complete. Series commenced at 12 o'clock, midday. 



Tor the purposes of the experiment the following reactions may be con- 

 sidered to be of different grades : (marked by degrees) 1°, 0° ; (marked by 

 millimetres) 149, 148, 145, 147, 141, 144, 143, 142, 140, 139, 138, 137, 135, 

 136, 134, 133, 132, 129, 130, 128, 127, 126, 123, 121, 117, 120, 118, 116, 100, 

 90 = circa 32 grades. 



Before this series was taken a " quick " series showed greater grading — 

 between a minimum of 30° at 150 mm. and 90 mm. (coils in line). But in 

 the figure the grading is over a range of about 150 to 90 mm. only. 



After the series here reproduced was taken the remaining intact branch of 

 the motor nerve was ligatured. Thereafter no reflex contraction was evoked 

 on stimulation with the strongest stimuli here used. It was later found that 

 there were about 28 fibres in that branch of the nerve. Of these probably 

 about nine were afferent fibres. 



Here, therefore, a number of grades which is probably about 30 was 

 conditioned by the reflex activity of about 20 efferent nerve fibres. 



