52 E. F. MACNICHOL, jr. 



dissection of the husk of the ommatidium is possible or that a digestion with 

 enzymes will facilitate its removal. This still remains to be tried. 



We may also get clues from the work on other receptors having analogous 

 properties. The beautiful work of Kuffler (1954) and Eyzaguirre and Kuffler 

 (1955) on the abdominal stretch receptors of crustaceans in many ways parallels 

 our own but is far more complete. Here they have shown that a single cell is 

 capable of giving a slow potential in response to a mechanical stimulus, that 

 the slow potential appears to cause the generation of spikes, and that there are 

 direct inhibitory connections to the cell. Since the tissue is transparent and the 

 cell is large, they are able to place their microelectrodes in axon, soma and 

 dendrites at will. We hope that the type of activity that they are obtaining in 

 different portions of the cell will give us clues as to where our electrodes are 

 placed even though we cannot see their tips. 



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