; 
4 
that he was dealing with Tilletia laevis. He mentions several 
methods of prevention by means of seed treatment. 
Volkart (884) quotes Prévost to the effect that sulphate of copper 
was also recommended by Tessier. 
Bryant (69) states that the treatment of seed wheat with salt brine, 
soap lees, and lime had been practiced in England for generations 
prior to 1784. He believes it to be useless for prevention of bunt 
and injurious to the seed. He also states that the farmers knew it 
to be ineffectual, but that they persisted in it because it was a time- 
honored habit. He made a careful examination of the bunted heads 
and gave a correct morphological description of them, including the 
aborted stamens. He was convinced that atmospheric or other ex- 
ternal factors caused the shrinking or hardening of the ligule at the 
base of the flag leaf, thus causing the young head to be compressed 
in emerging from the boot. This supposed interference with the flow 
of the sap he believed resulted in the abortion of the stamens and 
consequent failure of fertilization, in which case bunt was produced. 
Where the compression was more severe, both pistils and stamens 
were aborted, and loose smut resulted. This was an ingenious the- 
ory. Bryant clearly failed to discover the presence of bunt in the 
young head before it was subjected to this pressure. The ideas here 
expressed were common, in a more or less modified form, during the 
eighteenth century and, together with the idea of injurious or poison- 
ous dew and disordered sap, dominated the pseudoscientifie thought, 
at least down to the time of Tillet’s discoveries. Meyen (268) was 
absolutely certain that smuts of cereals were not infectious diseases 
but were due to stagnation of the sap, caused by overfertilization or 
improper fertilization of the soil. 
The work of Prévost (3/2) was a distinct contribution to our 
knowledge of the smuts. He observed the germination of the spores 
of Tilletia and the production of the primary and secondary sporidia. 
He also tried to demonstrate the entrance of the fungus into the © 
seedling. 
Tulasne (577) carefully followed up and confirmed Prévost’s work 
and established the genus, naming it Tilletia in honor of Tillet. In 
his second memoir, 1854, he figures the germination and development 
of Tilletia as far as the formation of the secondary sporidia. There 
was now no logical ground to doubt the parasitism of this smut, 
although no entrance to the host plant had been demonstrated. 
Berkeley (43) says that 1t has been known for many years that the 
principal diseases of cereal plants, such as rusts, bunt, mildew, ete., 
are of vegetable origin. Further, he states that, in spite of Unger’s 
(380) attempt to overthrow this theory, the work of Cordu, Léveillé 
(239), and others had completely established the fact that the pecu- 
liar structures found in plant lesions were not modifications of the 
host tissue, but that they sprang from a distinct mycelium and were 
as certainly vegetable as other fungi. In thesame article, Berkeley re- 
ports bunt studies carried on by him during the year 1846 for the pur- 
pose of demonstrating the parasitism of the organism as well as the 
method of infection and the physiologic relationship of the fungus to 
the host. He observed the germination of the spores and the pro- | 
duction of sporidia, though he did not recognize the latter as belonging ~ 
to Tilletia, Ba thought 1t a Fusarium attacking the bunt. Farther — 
on he states that in one case he observed on a bunted plant a streak — 
6 BULLETIN 1210, U. S. DEPARTMENT OF AGRICULTURE. 
