220 RESEARCH IN PROTOZOOLOGY 



tant, phase of this work. I refer to the study of post-mortem 

 material and, I may add, it should not be too far post mortem. 

 Wenyon's brief study (1920) is the only recent instance I can 

 recall where real use of such material has been made in connec- 

 tion with the study of the flagellates. Material of this kind could 

 afford a valuable means of control on these studies. Undoubtedly, 

 much of it can be obtained by an alert man who keeps track of 

 the patients in a charity hospital, many of whom are available for 

 necropsy immediately after death. 



It is not generally appreciated what excellent material may be 

 obtained in the state prisons and penitentiaries. Once official bar- 

 riers are passed" there usually is no difficulty in getting the men 

 to volunteer for experimental work. A certain proportion of them 

 always will be found to be infected with intestinal parasites, and 

 as all of them are under good sanitary control, the opportunities 

 are excellent for well controlled work, such as Walker (1913a) 

 performed at Bilibid Prison in Manila. Particularly valuable are 

 the opportunities afforded by men condemned to death. 



It is here that there is great promise of clearing up obscure 

 points on the relation of intestinal parasites to the host tissues and 

 where we may find our explanations of reactions — or the lack of 

 reactions. 



In doing this work I have found it desirable to organize the per- 

 formance carefully and rehearse it until everything runs smoothly 

 and quickly, for when the formalities are over and the cadaver has 

 been released by the authorities, the work must be done quickly if 

 the best results are to be obtained. 



The first requisite is to secure the aid of a pathologist who is 

 expert at post-mortem technique. He should clearly understand the 

 nature of the study that is to be made that he may plan his work 

 so that the microscopists and others shall receive their material 

 quickly and in good order. There should be a sufficient number of 

 persons present to carry out the operations without delay. The 

 exact sequence and methods to be used will have to be governed 

 by the nature of the case. 



I consider it unnecessary to describe the technique that will be 

 employed in the study of living and fixed organisms and tissues. 

 Dr. Andrews has written on cytological and other technique in 

 another chapter of this book, and men undertaking such problems 

 naturally will be trained in the work. Moreover, methods will have 



