2 BULLETIN 842, U. S. DEPARTMENT OF AGRICULTURE. 
sir able and timely to bring to general attention the data at hand, so 
that the disease may be more readily recognized, its further importa- 
tion and distribution prevented, and its control understood. 
HISTORY. 
Xeedham (24) / in 1743, in making microscopic examinations of 
supposedly smutted grains of wheat, found that they contained nu- 
merous motionless, eelworm larva? instead of spores. TThen placed 
in water these larvae soon began eellike movements; hence, there is 
this definite evidence of the occurrence of the disease in England at 
this early date. At that time Xeedham briefly recorded his observa- 
tions and again in 1745 (25) described the results of further investi- 
gations, but was unaware of their full significance until KofTredi in 
1775 (30) and 1776 (31) published the result of accurate investiga- 
tions covering several years, which clearly showed for the first time 
the causal relation of the nematodes to the malady and shed con- 
siderable light on the life history of the parasite. In 1799, Steinbuch 
(34) dealt with a disease of wild grass caused by a nematode which 
he called VibHo agrostidis and considered different from the wheat 
eelworm. He appears to have been the first investigator who pro- 
posed a name for the latter organism. He first refers to the parasite 
in these words, " und welche Vibrio tritici genannt werden konnte," 
and subsequently uses the name Vibrio tritici many times and in such 
maimer as to show conclusively that it is the wheat nematode of 
which he is speaking. Bauer (3), in 1823, after considerable study 
of and experimentation with the organism, also named it Vibrio 
tritici, apparently unaware of the fact that it had been previously 
thus designated by Steinbuch. Although Steinbuch was the first to 
apply the binomial, Bauer seems to have been the first to use the name 
systematically for the parasite. This doubtless accounts for the fact 
that many later investigators cite him (Bauer) as authority for the 
species. Dujardin (13), in 1815, transferred the species to the genus 
Ehabditis. Ehabditis is a genus described by Dujardin and contains 
mostly free-living forms which have little in common with Tylen- 
chus. Diesing (12), an eminent systematic helminthologist, in 1850 
also made a similar classification of the parasite. He placed it in the 
genus Anguillula described by Hemprich and Ehrenberg. This 
genus contains the vinegar eel and other free-living forms. Assum- 
ing that the parasite occurred on other grasses than wheat, he ac- 
cordingly called it Anguillula graminearam Diesing. In his classical 
monograph, Bastian (2) in 1861, correctly transferred the old spe- 
cies name as used by Steinbuch, i. e., tritici, to the genus Tylenchus. 
1 The numbers in parentheses refer to " Literature cited " at the end of this bulletin. 
