8 HISTORICAL NOTES ON BEE DISEASES, 
The writings of all these men should be read. If an investigator 
has done work on the causes of other diseases than bee diseases, but 
chooses to write on bee diseases, the reader will usually profit by 
reading his papers. The great mass of literature, on the other 
hand, created by those who have not worked on the cause of any 
disease can as a rule with profit be rejected. _ 
Having determined whose papers should be read, the character 
of the work of each investigator should be carefully noted. If the 
character of a man’s work proves to be good, give weight to all his 
statements, but if the character of a man’s work is poor, expect 
untrue statements and erroneous conclusions. If one wil learn in 
this way to judge the different papers, one will soon know what to 
believe and what to suspect, but if one does not learn to do this he 
will be forever at the mercy of printed pages. 
As the reader forms his opinion of the character of the work done 
by the different men referred to in this bulletin, permit the sugges- 
tion that he exercise some leniency inasmuch as the time at which 
a man works and the circumstances under which he labors are 
frequently in a measure responsible for mistakes. The reader will 
note, however, that many times the mistakes made in the study of 
bee diseases have been made only because insufficient and careless 
work was done by the investigator. In such cases no leniency is to 
be exercised in arriving at conclusions. 
The writers of this bulletin have commented very little on the 
character of the work done by the different authors of the papers 
reviewed. ‘The views of these men as they are found in the papers 
are given and the reader is allowed and urged to judge for himself 
whether or not such views are true. To aid the reader, however, 
the writers have made a few suggestions when it was thought that 
they might prove advantageous. The page references refer to pages 
in this bulletin. 
In reading a paper there is always the danger of misinterpreting 
an author’s conception. This danger is greatly increased if the 
author of the paper criticized uses a foreign language. Realizing 
this possible source of error, we have endeavored in every case to be 
cautious. When quotations from papers written in a foreign lan- 
guage were selected, rather free translations of them into English 
have been made. 
We disagree with a very large number of the statements which 
have been made by different authors referred to in this bulletin con- 
cerning the causes of bee diseases. Therefore let it be emphasized 
that the reviews which are here made are intended to express the 
opinion of the author of the paper reviewed, and not by any means 
the opinion of the writers of this bulletin. 
