Repository: UIHistories Project: Board of Trustees Minutes - 1888 [PAGE 214]

EXTRACTED TEXT FROM PAGE:

A DISEASE OF BKOOM-COKN AND SORGHUM.

217

So far as I am informed, this completes the accounts that have been published having reference to the particular and conspicuous injury under discussion. If the references really are complete, it is easy to understand that very little has been known upon a disease of long standing, and of wasteful effects.

A MICROBE CONNECTED WITH THE DISEASE.

In July, 1886, I collected for microscopical examination some of the diseased plants, and, upon using higher magnification than formerly found numerous bacteria within the affected tissues. An assistant in the State Laboratory of Natural History, Mr. Chas. Woodworth, was then asked to make special observations and experiments. The results were speedily convincing that a specific micro-organism was in some way connected with the disease, and apparently as cause. But for some reason still unknown, after August 1, 1886, the inoculation experiments undertaken were not successful, and, other work pressing, the matter was dropped for the time. A pure culture had, however, been made of a Bacillus from the affected plants, and the disease had apparently been produced by the use of this artificial culture. Seeds of broom-corn were planted in the green-house in February, 1887, and April 6th, Mr. M. B. Waite, at the time a senior student, commenced experiments upon the young plants from material taken from old diseased stalks obtained at the time from the fields. This old stock was found to contain great numbers of living microbes, similar to those obtained by culture. There were also found in the old material many spores of bacilli, recognizable by their shape, size, and peculiar optical characteristics. The cultures from this old material were not always pure, but the prevailing organism was a Bacillus, of recognizable peculiarities, and evidently the same as that found the year before. This organism was easily obtained in a state of purity, by means of plate cultures, and was also found to be pure in several direct transfers from the old stock. The inoculation experiments upon the young plants were at once successful, both from macerations of old material, and from the pure cultures of the Bacillus. Checks were made upon the same or similar plants by the use of sterilized water, and of sterilized fluid, like that in which the cultures were made, viz.: beef broth and potato infusion. Studies were prosecuted until the first of June, when they were again interrupted to be resumed a month later. The gentleman last named continued the work when taken up again, but my own attention was more directly given to it. Without pausing now for the detailed record of experiments, a general summary of results is presented.

U. 1.-15.