The Ohio Naturalist. 
[Vol. XIII, No. 8, 
150 
attention to this tobacco trouble, stating that it had occurred in 
the East Indies in 1888. The next investigator of this problem 
whose work attracted attention, was Iwanowski (1892, 1899, 
1903), who most emphatically pronounced mosaic disease to be 
bacterial in nature. Prillieux and Delacroix (1894), describe 
the disease, believing that it is similar in nature to a spot disease 
occurring on Cyclamen. Marchal (1897), mentions mosaic dis¬ 
ease and its treatment. Koning (1897), describes specific organ¬ 
isms which are supposed to be associated with this disease. Bey- 
erinck (189S), and Sturgis (1899), both published papers. The 
former author propounded the “contagium vivium fluidum” 
theory, while Sturgis regarded it as a physiological trouble. 
The following year (1900), Sturgis published the results of ex¬ 
periments in shading and liming tobacco plants. Woods (1899) 
presented his paper on the destruction of chlorophyll by oxidizing 
enzymes, with special reference to mosaic disease. According to 
Hunger (1905, p. 262), Dr. van Breda de Haan (1899), isolated 
bacteria from the tissues of diseased plants, said to be affected 
with mosaic. In (1900) Heintzel published a paper on tobacco 
mosaic and Behrens mentioned a disease of the tobacco which 
resembled mosaic in its symptoms and characteristics. Gontiere 
(1900), in a short review gives recommendations for treating 
seed and seed-beds. Woods (1902) revolutionized the interpre¬ 
tations of this malady, by propounding his enzyme theory and 
Hunger (1902, 1904), believed that he had eliminated bacteria 
as the causal organism. But nevertheless in the following year, 
Hunger (1903) (a) severely criticised Woods’ enzymic theory. 
Suzuki (1903) studied a peculiar variegation of the leaves of the 
mulberry, obtaining results similar to those of Woods’ on tobacco. 
Hunger (1903) (b) published other work explaining some of the 
ways in which this disease is spread. In the same year Boyugues 
(1903), cites definite data, dealing with the incubation of mosaic 
disease; he also seems to have made an anatomical study of the 
trouble. That laborers are responsible for the spreading of this 
disease in part, is shown by Hunger (1903). Selby (1904) con- 
finned some of Hunger’s infection experiments, showing that 
the disease could be disseminated by alternately touching dis¬ 
eased and healthy plants. In (1905) Hunger published a detailed 
treatise on mosaic disease, treating of its history, theories and 
experimental data. Delacroix (1905) found that a bacillus is 
associated with mosaic disease, and gave its exact measurements. 
Clinton (1908) mentions tomato chlorosis and its characteristics; 
he speaks of a similar malady on lima bean. Later (1910) he 
mentions as similar troubles, chlorosis of the squash, muskmelon 
and tobacco. Tomato mosaic is treated and compared with the 
same disease of tobacco by Westerdijk (1910). Loedwijks (1910) 
shows how colored light and light intensities effect the behavior of 
