474 L - V - HEILBRUNN. 



did not cease, and cleavage delayed but not stopped. In 2^/2 

 per cent, ether, cleavage -was stopped and, both by means of the 

 needle and by the cessation of Brownian movement, this was 

 shown to be accompanied by a decided increase in viscosity 

 (cf. p. 300)." 



The first sentence of the above quotation is not quite true. 

 As already pointed out Weber's ideas on ether narcosis agree 

 exactly with mine. But this is a minor point. The essential 

 fact is that Chambers has apparently obtained actual experi- 

 mental results in direct contradiction with mine. How can this 

 be interpreted? 



In a previous paper I have already taken occasion to criticize 

 the microdissection method for its over-great subjectivity (22), 

 and this criticism has been supported by Heilbronn (23). But 

 Chambers claims that his results were obtained both by micro- 

 dissection and by the observation of Brownian movement. For 

 some time I was puzzled as to how to explain the difference in 

 his findings. Finally the idea suggested itself that Chambers in 

 his studies of Brownian movement may have subjected the eggs 

 to heat. It has already been shown that heat and ether act 

 together, so that in low concentrations of ether, heat coagulation 

 is hastened (24). Such coagulation is moreover reversible. On 

 questioning Chambers it was found that in his experiments an 

 arc lamp was used for illumination and no special precaution 

 was taken to eliminate the heat factor. Here then is an explana- 

 tion of the divergent results obtained by the Brownian movement 

 method. As for Chambers' results with the microdissection 

 method, these are probably not very trustworthy, for he was 

 doubtless influenced by the results of his Brownian movement 

 investigations. Another worker, Hyman, also using the dis- 

 section method, has roughly confirmed my views concerning 

 the effects of ether on the protoplasm of sea-urchin eggs (25). 

 Miss Hyman used ordinary steel needles instead of a microdis- 

 section apparatus. 



SUMMARY. 



i. Water enters etherized muscle less rapidly than normal 

 muscle, but this does not necessarily imply a change in the 

 properties of the plasma membrane following etherization. 



