364 W or maid. — ‘ Brown Rot ’ Diseases of Fruit Trees. 
years previously found apothecia which had developed from mummied 
peaches; this form Norton himself referred to Sclerotinia fructigena , but 
Aderhold and Ruhland (1905) concluded that it was A. cinerea. 
Westerdijk, in 19x2, discovered a Sclerotinia on mummied cherries 
which, from the dimensions of its asci and ascospores, appeared to be 
different from S. fructigena, S. laxa , or 5. cinerea ; the direct connexion 
between the ascospores and a conidial stage was not traced however. 
That Monilia was a genus which was to be considered as of economic 
importance was recognized by von Thumen in 1875, and in the following 
year by Hallier. Soon epidemic outbreaks of diseases caused by Monilias 
of fruit trees on the Continent resulted in the publication of many papers 
on the subject, particularly during the last decade of the nineteenth 
century, when articles appeared under such well-known names as Schroter 
(1893), Wortmann (1895), Wehmer (1895-6), Frank (1898), Frank and 
Kruger (1897-9), Aderhold (1897), Woronin (1897-9), Goethe (1898), 
Behrens (1898), Muller-Thurgau (1900), Sorauer (1899), and others, 1 the 
years 1897-1900 being prolific in references to epidemic outbreaks of Monilia 
diseases. In Germany the first serious complaint of such an epidemic 
appears to have been in 1894 ; thus Frank and Kruger write in 1899, £ Die 
erste Klage iiber das epidemische Auftreten der Monilia-Krankheit . . . wurde 
in Deutschland im Fruhling 1894 laut, wo die landwirtschaftliche Hochschule 
in Berlin uber das allgemeine Absterben der Kirschenbliiten in der 
Ortschaft Blankenfelde bei Berlin um Rat befragt wurde’. 
Since 1900, Aderhold, Muller-Thurgau, and Sorauer have continued 
their observations, and others have taken up the work or recorded the 
damage caused, e.g. Ritzema Bos (1903), Molz (1907), Kock (1910), Muth 
(1910), Ewert (1912), Voges (1912), Westerdijk (1912), Broz (1913), and 
Eriksson (1913). 
In 1818 Ehrenberg discovered a form on apricots which he named 
Oidium laxmn ; as with O. fructigenum, this fungus has also been referred 
to other genera, its synonomy being as follows : 
Oidium laxum , Ehrenb. Sylv. (1818), p. 10,-22. 
Acrosporium laxum , Pers. Myc. I (1822), p. 25. 
Oospora laxa , Walk. Plor. Crypt. (1833), n. 1 574. 
Monilia laxa , Sacc. et Vogl. Sacc. Syll. Fung. IV (1866), 35. 
Sclerotinia laxa (Ehrenb.), Aderh. et Ruhl. (1905). 
Aderhold and Ruhland (1905) found the apothecial stage of this fungus 
in 1904 developing from mummied apricots which had been placed in soil 
in pots and kept under observation; they cultivated the ascospores on 
artificial media and reproduced the conidial stage. Since that date the 
name Sclerotinia laxa has been generally reserved for the form producing 
1 See Bibliography. 
