| Re Se 9. | 
8 BULLETIN 1210, U. S. DEPARTMENT OF AGRICULTURE, == 
a 
Jensen (184) suggested the possibility of blossom infection in case 
of the loose smut of barley. His deductions, based on certain experi- 
ments and observations, were briefly as follows: 
(1) He was unable to produce infected plants by applying spores to the seed. 
(2) Seed taken from a field in which loose smut had appeared produced infected 
plants in spite of treatment with copper sulphate, while seed from a clean field pro- 
duced a clean crop. 
(3) Seed treated with copper sulphate produced a smutty crop, while the same seed 
treated with hot water produced a clean crop. From these facts, Jensen reasoned that 
either an internal infection had obtained or that the spores were lodged between the 
grain and its adhering glumes. . 
Maddox (255) demonstrated the blossom infection of the loose 
smut of wheat. This was fully confirmed by Brefeld (61) in 1903, 
Hecke (144) in 1906, and Hori (/70) im 1907. ’ 
After this date the history of the investigation of the bunt and 
loose smut of wheat becomes for the most part dissociated. Before 
taking leave of the subject of the loose smuts, a few words should be 
said about the contributions of Maddox to the discovery of blossom 
infection, inasmuch as he has never been accorded the complete 
recognition he deserves. His methods of investigation are best 
expressed in his own words, quoted in 1896 in the Agricultural 
Gazette of Tasmania: 
I will now give the conclusions I have arrived at with smut [of wheat] from the results 
of my experiments. I have never been able to cause infection and reproduce the 
disease with spores on the grain or in the ground, which I can so easily do with bunt 
spores to reproduce bunt. The only way I have been able to infect grain and repro- 
uce smut (which seldom ever fails) is by putting the spores on the ovary of the plant 
at flowering time, about the same time as the pollengrains are beingshed. The grain 
will mature without the slightest signs of being diseased. I have hit the time so well 
now that I may say I never have a failure. I think this accounts for when I did fail, 
viz, the ovary was not forward enough for the spore to get its seed bed, or possibly 
sometimes the spores were not matured enough. The comparison of bunt and smut 
spores finding their seed bed are the very opposite. It is really wonderful to me how 
the smut oe do, as the ovary is well protected by the glumes or chaff, and there is 
no doubt that here we have a practical demonstration of the fact that infection by the 
loose smut of wheat occurs during the flowering period and that this is the first record 
of it. 
MeAlpine (252) in his ‘Smuts of Australia,’ 1910, accords due ree- 
ognition to Maddox by quoting the foregoing paragraph. On the 
other hand, Kirk (2/1), in the Annual Reports of the New Zealand 
Department of Agriculture, gives the entire credit to Brefeld and 
Hecke, with no mention of Maddox. 
Lang (23/) published his conclusions from somewhat extenstve 
investigations of the physiologie relationships of the smuts to their 
hosts and of their modes of infection. His studies were confined to 
Ustilago tritici (Pers.) Jens. and to the smuts of oats and barley, 
but it is of interest to note that he found them all to be intercellular 
parasites and that they obtained their nutriment through thei high 
osmotic power. So far as the seedling infection in case of oats and 
barley is concerned, he is of the opinion that the entrance of the 
parasite is promoted by the degeneration of the cells of the leaf 
sheath, if not entirely dependent on it. 
In the period following the final determination of the parasitism 
and the mode of infection of bunt and extending to the present time, 
much investigation has been carried on and a great volume of litera- 
ture published. This work and publication can be grouped under 
; 
