98 HISTORY OF PHYTOPATHOLOGY 



school of phytopathologists, the predispositionists. The 

 Kiihnian period had produced but one predispositionist 

 of note, Ernst Hallier, whom I have already mentioned. 

 The Millardetian period was but little more fortunate 

 as to the number of disciples of this doctrine. On the 

 other hand, the great predispositionists of this quarter- 

 century were to far outshine in ability and success their 

 predecessor of the earlier period. This doctrine so 

 inauspiciously launched by Hallier was to find master 

 champions in Sorauer of Germany and Ward of Eng- 

 land. 



Paul Carl Moritz Sorauer was born in 1839 and died 

 January 9, 1916, at the age of seventy-seven. 1 Of his 

 early life and training I am unable to write. His biog- 

 raphy is not as yet available to us. Like his German 

 contemporaries of this period, he was already trained 

 and had made some contributions to the science before 

 the advent of the Millardetian period. The most note- 

 worthy of his pre-Millardetian writings is the first edition 

 of his handbook and his book on fruit diseases. (See 

 footnotes 2 and 3, page 57.) 



Sorauer, unlike. Hallier, was largely free from the 

 theories and dogmas incompatible with the scientific 

 progress of his time. He was, nevertheless, an uncom- 

 promising predispositionist, and it is safe to assert that 

 the modern interpretation of the doctrine of predispo- 

 sition as set forth by Sorauer has much in it for thought- 

 ful consideration by pathogenetists. That external fac- 

 tors, such as temperature, moisture, and nutrition, may 

 gravely affect the constitution of the individual plant as 



1 A notice of Sorauer's death is to be found in Hedwigia, Beibl. 

 57 : 151, 1916. 



