243 



6. Prunus Amygdalus, Stokes, and cultivated varieties of 



Almonds. 



P. Armeniaca, Linn, and cultivated varieties of 

 Apricots. 



*P. Avium, Linn., Gean. 



*P. Cerasus, Linn, and cultivated varieties of cherries. 



*P. communis, Hudson. AVild Plum. 



fP. japonica, Thunberg. 



*P. lusitanica, Linn. Portugal Laurel. 



*P. spinosa, Linn. Sloe. 



*fP. acida, Ehrhart. vnr. flore pleno. 



7. Cultivated varieties of Plums: — 



Pond's Seedling. ^Victoria.' 



Monarch. *Czar. 



Gisborn. ^Belgian Purple. 



Several gages. *Damsons. 



8. Stocks used for grafting : 



*'tThe Brompton. 



* t Myrobella (Pr u n us my robolanus) . 

 *t Common Plum stock var. 



Saxifragaceae. 



*fRibes cereum, Douglas, and cultivated varieties of Goose- 

 berries and Currants. 



Leguminoseae. 



* Laburnum, vulgare, Presl. 

 *t£. alpinum, Presl. 



Oleaceae. 



Syringa sp. 



Sapindaceae. 



Aesculus Hippocastanum, Linn. 

 *\A. carnea, Hayne. var. Briotii. 



Ericaceae. 



*fPernettya mvcronata, Gaudich. 



+Xoted by Mr. F. J. Chittenden at the E.H.S. Gardens, Wisley. 



All material used for examination, as described in this paper, 

 was secured from naturally infected "silvered" plants growing 

 in the open, not from artificially inoculated plants, 



oni 



be 



The plants were 



m 



irked in the field during the summer of 1918, and from 

 October onwards, and material was taken, as required, to the 

 laboratory. Unfortunately the leaves could not in all cases be 

 examined, as the majority of plants were of a deciduous character, 

 so that the leaves had dropped before the microscopic detail- 

 could be studied. 



The tracing of the fungus in diseased tissues is by no means 

 an easy task, owing to the fact that the hyphae are extremely 

 fine. * The following method was adopted: — The material was 



Cut into cubes of about 1 cm. and steeped for 6-8 days, or even 



mater 



solution of picric acid in 50 per cent, alcohol. For sections, 



a2 



