168 Annals Entomological Society of America [Vol. XIV, 
known to undergo a part of their development in insects. It is 
rather my desire to show that long before the amazing discov- 
eries of the relation of mosquitoes to malaria, and the other 
contributions of the past twenty-five years, the foundation 
was being laid. Without that foundation the building could 
not have been erected. Would it not be interesting 1f today we 
could tell what stones are being rejected which may become 
the cornerstones of the future? 
Above all, a review of the history of any theory emphasizes 
the fact that no man lives to himself alone, and that no honest 
effort to get at the truths of nature, no matter how insignificant 
they may seem, is without its value. The man who scorns 
scientific work which has not an obvious utilitarian trend is 
ignorant of the history of applied science. The scientific worker 
who tries to build about himself and his subject a wall of defense 
against impractical ideas or against what he regards as rival 
subjects, will merely succeed in insuring himself against 
recognition by his followers. 
