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SCIENCE. 



[N. S. Vol. XV. No. 381. 



the polymorphism of species whereby an 

 organism could change into, practically, 

 whatever happened to grow in its vicinity; 

 while Pouchet in Prance and Bastian in 

 England were maintaining the spontaneous 

 generation of minute organisms in sterile 

 liquids with great vigor and a considerable 

 following, if not with much logic. Every- 

 where the old, well-intrenched theories of 

 disease were in conflict with the new. Dur- 

 ing the whole of this period the doctrines 

 of Dai'win were opposed and fought over 

 with a pertinacity and a rancor scarcely to 

 be appreciated by the younger men of this 

 generation. Evolution has now become our 

 watchword, but even yet we do not fully 

 appreciate what it means, or at least we 

 often speak and write as if we did not. It 

 is too large a thought, and we are still en- 

 tangled in the language of our ancestors. 

 Especially do we not fully appreciate the 

 molding influence of environment, i. e., 

 the plastic nature of the living organism 

 under the action of changed conditions. 



Prior to the year 1880, laboratory meth- 

 ods for the study of fungi and bacteria 

 were not well developed. In the first place, 

 there was no exact and convenient method 

 for obtaining pure cultures and, in the 

 second place, the microscope was still the 

 principal instrument of research. The few 

 experiment stations in this country and 

 those in Europe were, for the most part, 

 plodding along in a perfunctory way, with- 

 out good equipments and with little money 

 for botanical inquiry, and the study of plant 

 diseases was scarcely thought of outside of 

 a few xmiversity laboratories, and rarely 

 in these with anything practical in mind 

 for the benefit of agriculture. The main 

 thing considered was the parasite rather 

 than the host plant, and the technique for 

 the study of both was of the simplest sort. 

 We had no precise fixing and staining 

 methods, no fine microtomes with their 

 yards of serial sections, no synthetic cul- 



ture media, no elaborate sterilizing ovens 

 and brood chambers, and no apochromatic 

 glass for lenses. ' Pure cultures ' were 

 practically unknown, and photography and 

 photomicrography had not yet become arts 

 of daily use in the laboratory. 



Prior to 1880 we had indeed the brilliant 

 researches of Louis Pasteur on a variety 

 of subjects of wide interest to biologists, if 

 not bearing directly on plant pathology. 

 Berkeley had already done some good work 

 on plant diseases in England, although 

 most of his efforts had been devoted to sys- 

 tematic mycology. Tyndall in England 

 had also done much to clear away the fog 

 produced in the public mind by the adher- 

 ents to the doctrine of spontaneous genera- 

 tion. Kiihn, Sorauer, Frank and Hartig 

 had begun their studies in Germany. But 

 it was especially to de Bary, in Germany, 

 that all eyes were turned as the great mas- 

 ter mind. He had published a series of 

 brilliant papers on the life history of vari- 

 ous fungi, and was stimulating many of 

 the younger men to undertake a higher 

 type of research work than was then in 

 vogue. Among these men, "VVoronin de- 

 serves especial mention. He published sev- 

 eral fine papers in conjunction with de 

 Bary and has continued the good work 

 independently. In our own country. Dr. 

 Parlow had published a number of inter- 

 esting papers from the Bussey Institution 

 on black knot and other diseases of plants, 

 and there was some mycological work with 

 an economic aspect going on under Dr. 

 Burrill's direction at the University of Illi- 

 nois, and under Dr. Bessey's direction at 

 Ames, Iowa. In Europe and America, a 

 number of younger men, who have since 

 become widely known, were just beginning 

 their work on diseases of plants. 



Plant pathology was not an attractive 

 profession in those days. When he first 

 desired to make the diseases of plants, or 

 mycology, as we called it, his chosen pro- 



