1899] THE CEREAL RUST PROBLEM 345 
in the soil previous to such inoculation, as explained above, then 
Eriksson’s difficulty in accepting the presence of such mycelium as the 
cause of the disease, on account of its absence from the embryo, both 
before and immediately after germination, is removed. 
“Ce fut en vain que je cherchai a constater, par le microscope, 
la présence de germes infectieux internes. Certainement je découvris 
dans les tissus périphériques des graines du froment ridées et 
déformées par la rouille, un mycélium tres développé, et méme parfois 
des espéces de nids des spores @hiver (teleutosporae). Mais toutes les 
tentatives faites pour trouver un mycélium dans le germe lui-méme, 
que ce fit dans le germe renfermé encore dans la graine, ou dans le 
germe sortant de la graine a la germination, restérent infructueuses.” 
Many people have become so thoroughly accustomed to the annual 
loss of a certain amount of capital through “ rust,” “ bunt,” and “ smut ” 
of cereals, that it is looked upon as a matter of course; or, in other 
words, such loss is not realised at all; and it is only during seasons 
when these diseases are rampant that their presence is forced upon the 
cultivator, and even then only the amount of loss above the usual 
annual average is realised. The following figures, taken from official 
sources, illustrating the amount of loss sustained during an ordinary 
season, should be sufficient to explain why some governments have 
considered it incumbent upon them to aid in the endeavour to prevent 
such enormous losses. 
“Oat smut (Ustilago avenae) alone destroys each year in the United 
States over $18,000,000 worth of grain. The other grains, especially 
wheat, rye, and barley, also suffer severely from smut diseases; the 
amount, however, has not been overestimated ” (13). 
In the same country we learn that “The ageregate loss from 
‘rusts’ (Puccinia sp.) is estimated to be over $40,000,000 annually ” 
(14). 
The Prussian Statistics-Bureau states that the loss caused by 
“rust” alone on wheat, rye, and oats, in Prussia, during the season of 
1891, amounted to a little over £20,000,000 (15.) 
In Australia the loss in the wheat harvest of 1890-91, due to 
“rust,” has been estimated at £2,500,000. 
Finally we learn that in the United States, “ Probably it would not 
be overstating the loss from plant diseases, as a whole in this country, 
to place it at $150,000,000 to $200,000,000 annually ” (16). 
The amount of annual loss in Great Britain arising from plant and 
animal pests is not officially estimated, but it may safely be assumed 
that, if half the amount of loss could be prevented, farming and _horti- 
culture would prove to be remunerative occupations. 
An equally formidable array of figures could be quoted from 
official publications showing the actual gain derived by following the 
directions issued from experiment stations. 
The question that naturally suggests itself at this point is the 
