Placed ok a Nation-widc Basis 209 



licld experiments were arranged: "one with southern cattle and 

 ticks, a second with southern cattle from which the ticks were 

 removed, and a third over which only adult ticks had been 

 scattered. ... In the first field no natives died,"' reported Dr. 

 Theobald Smith in his account of " Investigations of the Infectious 

 Diseases of Animals," published in the report of the Chief of the 

 Bureau for the year 1890."'" " but careful examination of the blood 

 by the writer showed Texas fever in an unmistakable manner. In 

 the ' tick" field one animal died of Texas fever, and the examina- 

 tion of the blood showed that most other natives in the field 

 were sick. In the, third field containing southern cattle without 

 ticks no disease could be detected." Confirmatory and further 

 experiments followed in 1890, during which " ticks were hatched 

 artificially and placed on cattle with the result that Texas fever 

 appeared in every case." ^' 



Galloway, in his annual report as Chief of the Division of 

 Vegetable Pathology for the year 1891,''^ announced that Waite, 

 working mainly that year on the life-history of the pear blight 

 organism, had cultivated in the laboratory " the germ " on sterilized 

 nutrient media, and its life history, through culture study used in 

 field experiments, had been carefully examined, both at Wash- 

 ington and in orchards near Brockport, New York. Waite had 

 found that the 



germs normally gain an entrance through the tissues of the nectaries. At 

 other points the germs gain an entrance through a puncture or injury to 

 the epidermis. The germs multiply in the nectar of the flowers, and are 

 carried by insects from one flower to another. Bags of paper, cheese cloth, 

 mosquito netting, or in fact anything keeping the insects out, will preserve 

 the trees from blight. Certain varieties of pear, the Bartlett among them, 

 failed to set fruit when insects were excluded. Others, such as the 

 Dutchess and Seckel, did not need insect aid. 



More time and research would be required to transmute from 

 premise to conclusion, from observation to fact, another contri- 

 bution for which Waite is known— his concept of mixed plantings 



""Pp. 105-110, at pp. 107-108. 



"'T Smith and F. L. Kilborne, Investigations into the n.Uure, causation, and 

 prevention of Texas or Southern cattle fever, Bureau of Animal Industry, ^i^Jl/^'" 

 No. 1, 301 pp., 10 pis., 7 fifis., 1893. See also Experiment Station Record 4(9): 

 755-758, Apr. 1893, at p. 756. 



"Pp. 372-373. 



