89 
to ripen % It is true, refined investigations proved that the mycelium 
could be discovered in small quantities in the corn plants as they grew 
larger and older, but it seemed to do no harm; but are we to believe 
that this mycelium can go on growing in and with the tissues of the 
corn plant, only to exert their destructive effect months afterwards as 
the grain begins to ripen ? 
Astonishing as this may seem it turned out to be the-case. R. Wolff 
in 1873 repeated Kuhn’s experiments with smuts, etc., and practically 
confirmed them in every particular; it is true he went a little too far 
in concluding that only a certain organ (the first leaf sheath) is suscep¬ 
tible to the infection, and Kiihn’s results were shown to be more accurate 
in this respect, but the primary fact remains that thesporidia are able 
to effect an entry into the host-plant by means of their germinal tubes 
only, provided they attack the embryonic tissues, and especially the 
cells of these delicate young embryos; once inside, the delicate fungous 
filaments grow on with the tissues, gradually permeating every part of 
the plant until, with the development of the young fruit, they meet with 
the conditions for the fulfillment of their own last purpose—the produc¬ 
tion of spores. Further investigations only succeeded in demonstrat¬ 
ing the correctness, in all essential particulars, of these views. 
# # # # # * * 
DRESSING. 
As early as 1781, and even earlier, several observers had satisfied 
themselves of the infectious character of these diseases, and even in 1820 
it had been shown that washing the seed corn with copper-sulphate 
before it was sown resulted in a diminution of the number of dis¬ 
eased ears ; and many interesting experiments were made from time to 
time tending to prove that (1) if smutted grains are mingled with clean 
ones, the sowings give an enormously higher jmrcentage of diseased 
ears; (2) the more the seed-grain is cleaned from adherent spores, the 
less the percentage of diseased ears; (3) it is only in the early stages 
of the germination of the grain that the danger of the infection is 
great. 
It was from this foundation that the now well-known process of 
u dressing” wheat took its origin, and to this may be added some 
“ practical ” measures introduced as the outcome of experience, and 
taught empirically. Let us glance at the results in the light of what is 
already known. One of the commonest and best-known methods of 
“dressing” is to steep the grain for some hours in a dilute solution of 
copper-sulphate in water. The object is to cause so much of the poison¬ 
ous salt to stick to the coats of the u seed-grain ” as will kill the delicate 
promycelia and sporidia before the latter can penetrate the young corn 
plant. The chief danger is lest the young seedling should have its deli¬ 
cate tissues injured. Other dressings are used in addition to the above; 
salts of lime, soda, etc., arsenic, permanganate of potassium, carbolic 
