No. 631] SHORTER ARTICLES AND DISCUSSION 



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hard thing to realize, in such an investigation where one is at- 

 tempting to ascertain the relation of two widely different enti- 

 ties, that a single average case, even though admirably sectioned 

 and stained, may mean very little. Dozens of cases usually 

 afford a more comprehensive view; and finally one comes to be 

 able to piece together bits of information which make the story 

 clear. It would be miraculous if the keenest pathologist could 

 make clear the evidence from "five cases." Protozoan life his- 

 tories are not read in a moment, and a study of a hundred cases 

 for an hour means much more than one case for a hundred hours, 

 — unless that one case is exceptional. 



In concluding, it may be added that the writer hopes later to 

 consider more in detail the valuable constructive aspect of Dr. 

 Tyzzer's paper. It is freely admitted that the life history of 

 Trichomonas in the tissues is not wholly clear, and it seems pos- 

 sible that some of the forms referred to by Dr. Tyzzer are new. 

 This is especially true of some of the motile stages which, in the 

 tissues, lose their flagella and, as Schaudinn says, "audi mit 

 stump flobosen Pseudopodien umherkreicht." It will probably 

 be some years before the last word is said on the blackhead 

 problem; and yet we are progressing. Under an efficient smoke 

 screen Dr. Tyzzer has given the last blow to the "Amebic theory" 

 and already— though grudgingly— has yielded some support the 

 agency of the flagellates in cecal and liver infections. It may 

 be confidently expected that in the course of time his researches 

 will give more. 



Dr. Tyzzer closes his critical introduction with the following 

 words: "It may appear that the above discussion is unduly 

 critical of the findings of other investigators. The confused 

 state of the subject, however, appears to warrant drastic methods 

 and the singling out of various misinterpretations and incon- 

 sistencies, for it is quite evident that the enthusiasm of certain 

 investigators for their views has caused them to neglect impor- 

 tant facts." 



How we all wish to be such champions of the truth ! But, in 

 our war on "misinterpretations" and "inconsistencies" and on 

 "neglect of important facts," would not our scientific world be 

 a happier place, and all our work of greater merit, if criticism 

 were tempered more with keen insight and less with the ardent 

 spirit of academic chivalry ? Philip Hadley. 



Kingston, R. I., 

 October 9, 1919 



