THE UNGERIAN PERIOD 37 



disease abnormalities of plants" 1 appeared in 1839. 

 Wiegmann accepts Unger's explanation of the nature of 

 disease in plants and the relation of the fungi found as- 

 sociated with the lesions. He cites Unger's book exten- 

 sively, setting forth in much simpler language, however, 

 the autogenetic doctrine of disease in plants. Wieg- 

 mann's book differs distinctly from that of Unger in 

 that it purports to be a handbook for farmers and garden- 

 ers rather than a scientific treatise. He covers much 

 the same ground as Unger, but adds a discussion of 

 means of control, a phase of the subject not considered 

 by Unger. Wiegmann claims to have thoroughly tried 

 out the various remedies he recommends. 



Next to Unger, the most dominating personality in 

 the phytopathologic thought of the Ungerian period was 

 Meyen, a remarkable young botanist who at his death 

 was professor of botany at the Imperial University at 

 Berlin. 



Franz Julius Ferdinand Meyen was born at Tilsit in 

 Posen in 1804. He was the son of a bookkeeper in a 

 small store. Leaving the gymnasium early, he began 

 to study pharmacy, but eventually studied medicine, 

 taking his degree in 1826. He practised four years and 

 then went for a botanizing trip around the world. Re- 

 turning, he was made professor of botany at Berlin, 

 where he remained until his death at the age of thirty- 

 six. Meyen was one of the most brilliant and productive 

 botanists of this period. His writings cover the whole 



1 Wiegmann, A. F. sen. : Die Krankheiten und krankhaften Miss- 

 bildungen der Gewachse. Ein Handbuch fur Landwirthe, Gartner, 

 Gartenliebhaber und Forstmanner, pp. I-XII + 1-176, Braunschweig, 



96347 



