322 THOMAS J. HELDT 



nor above five years. The age of all the animals used lay well 

 within the limits noted but their weight varied between 10 to 

 19.7 kgm. 



Regarding the method of killing, the technique should produce 

 the least possible change in the nerve cell and at the same time 

 permit of taking the tissue in a minimal length of time. This 

 excludes the use of anesthetics, narcotics, and even hypnotics, 

 as well as death by shooting, hanging, stabbing, or asphyxiating. 

 The method finally decided upon was one of decapitation with 

 a double-guillotine, thus removing a segment of the neck includ- 

 ing the spinal cord. The apparatus used is composed of two 

 large butcher's cleavers, heavily weighted, and so bolted together 

 that they can be adjusted according to the length of the segment 

 of cord desired. The necessary accessories to the method con- 

 sist of a block sufficiently firm to receive the impact of the blow 

 of the decapitating apparatus without jolting, and thus permit- 

 ting of obtaining the segment desired at one blow ; and a strongly 

 made animal-board that can be closely and carefully adjusted to 

 the foregoing block. The animal-board is provided with straps 

 permitting of fastening the dog upon it quickly and conveniently. 

 The dog's neck, by means of a strap and collar, is stretched out 

 upon the block. For recording the time of decapitation and the 

 subsequent taking of the tissue a stop-watch was used. The 

 various details of construction and other minor aspects of the 

 method, so briefly and simply stated above, as well as the sev- 

 eral little difficulties confronted in its use are obvious and readily 

 remedied and so need no lengthy description. 



In taking the tissue it is of course essential that the assistants^ 

 be fully instructed as to the particular place they fill, and that 

 everything is in absolute readiness. For the decapitation is prac- 

 tically instantaneous and thereafter the tissue is immediately at 

 the disposal of the investigator. The segment of the animal's 



- It is with a feeling of deep obligation that the author expresses his indebt- 

 edness to Messrs. INI. D. Ott, H. L. Kearney, M. M. Miller, J. S. Homan, S. H. 

 Snider, W. H. Taylor, T. K. Kruse, and Geo. Klinkerfuss, for the assistance so 

 willingly and kindly granted. 



