THE MODERN ERA 43 



meister's 1 work on the animal parasites of man revolu- 

 tionized the theories on animal parasitism. Darwin's 

 painstaking researches into the origin of species 2 freed 

 the biologic sciences of the deadening dogmas of special 

 creation and fixity of forms. The wonderfully exact 

 and extensive studies of that master mycologist, Anton 

 de Bary, so completely established the independent na- 

 ture of entophytic fungi that the theory of their meta- 

 morphosis from the sap of diseased plants was no longer 

 tenable. 



The wide-spread and destructive epiphytotics of the 

 Phytophthora blight which swept the potato fields of 

 Europe in 1844 and 1845, 3 resulting in famine in some 

 sections, suddenly impressed everyone, layman and 

 scientist, with the importance of plant diseases in the 

 economic welfare of mankind. The most noted scientists 

 of the time turned their attention to the solution of the 

 problem thus presented. Learned societies and even 

 governments appointed commissions to investigate the 

 cause of the disease. This intensive investigation led 

 naturally to a more general and critical examination of 



1 Kiichenmeister, Friedrich : Die in und an dem Korper des lebenden 

 Menschen vorkommemden Parasiten. Ein Lehr- und Handbuch der 

 Diagnose und Behandlung der thierischen und pflanzlichen Parasiten des 

 Menschen, Abt. 1 : 1-XVI + 1-486; Abt. 2 : 1-X + 1-148, Leipzig, 

 1855. An English translation appeared in 1857 under the title: On 

 animal and vegetable parasites of the human body. A manual of their 

 natural history, diagnosis and treatment, 1 : 1-XIX + 1^143; 2 : 1-XVI 

 + 1-287. 



2 Darwin, Charles: On the origin of species by means of natural selec- 

 tion, or the preservation of favored races in the struggle for life, pp. I-IX 

 + 1-502, 1859. 



3 Jones, L. R. : Investigations of the potato fungus Phytophthora 

 infestans, U. S. Dept. Agr. Bu. PL Ind. Bui., 245 : 19-24, 1912. 



