Sclerotinia fructigena. 97 



developed coincident with the peach flowers. The ascospores 

 were readily germinated in water, bouillon and prune juice 

 and cultures made in agar and on sterilized dried apple and 

 prune, from which conidia were developed not distinguishable 

 from the Monilia associated with brown rot of fruits. In- 

 oculations of peach and plum flowers and fruits from asco- 

 spores or from these conidia developed in 2-4 days brown rot 

 and clusters of Monilia conidia. Monilia fructigena^ Per- 

 soon, is then properly referred to Sclerotinia fructigena 

 (Persoon) Schroeter. 



EXPLANATION OF ILLUSTRATIONS. 



PLATES XVIII-XXI. 



Plate XVIII. — Sclerotinia fructigena. 1, Ascus and paraphyses, X700; 

 2, Spores, X 7C0; 3-5, Germinating spores, X 700; 6, Spores in end of ascus 

 germinating, the lower spore natural size, the others swollen, X 1,000; 7, 

 cross section of disk of apothecium, the base of the asci shown at a, b the 

 cortex on the outside (somewhat diagrammatic), X^O; 8, 9, Mycelia from 

 bouillon drop cultures with clamydospores(?) forming in the cells, — some 

 sporidiaf?) shown in 9, X 1»000; lOj End of hypha on plate culture, 

 shown in plate XX, X1>000; II, 12, Conidiophores arising from branches of 

 mycelium produced from ascospores. The chains of conidia were drawn 

 from those that bad fallen over and the conidia separated, X SO; 13, Chains 

 of conidia attached, X 700. 



Plate XIX. — Sclerotinia fructigena. Upper figure. Looking down upon 

 a mummy peach surrounded by apothecia, natural size. Lower figure. 

 Apothecia attached to mummied fruits; on the left appearing through the 

 soil; in the center detached fragment showing the stipes, natural size. 



Plate XX. — Mycelium of Sclerotinia fructigena, with clusters of conidia 

 from agar plate culture developed from ascospore, X 6- 



Plate XXI. — Fruits inoculated with ascospores of Sclerotinia fructigena. 

 The plum in the upper left hand corner covered with a dense mass of 

 hyphae bearing conidia in the grey spots at the left. To the right a peach 

 and below an apple and plum, check cultures, simply pierced by sterile 

 needle. The other two peaches on the right inoculated like the plum at the 

 top. The middle peach shows at the right the usual form of clusters of 

 conidia. All natural size. 



Issued August 23, 1902. 



