$2 Dr. A. J). Waller. The hereto-motor Effects in [Jan. 16, 



of the chromosomes in synapsis is such as to prevent any subse- 

 quent separation, the result being that no sex-cells can be organised, 

 since the essential condition of a qualitative separation of the chromatin 

 is not fulfilled. 



" The Secreto-motor Effects in the Cat's Foot Studied by the 

 Electrometer." By Augustus D. Waller, M.D., F.K.S. 

 Eeceived November 17, — Eead November 19, 1903. Ee- 

 ceived in revised form January 16, 1904. 



In a previous communication* it was stated that the electrical signs 

 of secreto-motor action by tetanisation of the sciatic nerve are 

 demonstrable in the pads of a cat's foot after death, best so during 

 the second half-hour after death, when the action of the nerve upon 

 muscles of the limb has ceased. 



The subsequent study of these effects, by means of electrometer 

 records, has brought out with great distinctness the chief classical 

 events with which we are familiar in the case of the contraction of 

 voluntary muscle, viz., the latency and course of a single response 

 to a single stimulus, the super-position of two or more responses and 

 the composition of tetanus, summation of stimuli, fatigue and recovery, 

 and the staircase phenomenon. The difference between the muscular 

 and the secreto-motor series of phenomena is principally a difference of 

 time, the former being about 100 times more rapid than the latter. 



I may preface the description by stating that I have experimentally 

 satisfied myself that the electrical effects are in reality of glandular 

 origin. The response is completely abolished by atropine, and it 

 is restricted to the pads (glandular) of the skin, being completely 

 absent from the hairy (non-glandular) skin, i.e., it is not a pilo-motor 

 concomitant. 



The description itself will be best given by means of the following 

 electrometer records of : — 



1. A single response to show the latent period and duration of the 



response. 



2. A series of single responses to show staircase phenomenon. 

 •3. A series of four responses to show composition of tetanus. 

 4. A series exhibiting post-mortem decline. 



* ' Proc. Koy. Soc.,' November, 1901, " On Skin-currents. Part II. — Observa- 

 tions on Cats." The electrical effect of indirect excitation is always ingoing 

 through the skin. This direction has been conventionally indicated throughout 

 this paper by a downward movement of the mercury column. 



