30 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



thick) ; oonidia broadly elliptical or almost subglobose, nearly colourless 

 (10 12 n diam.), collected in somewhat globose heads. 



It is hopeless to dream of saving the fruit when once attacked, but 

 all diseased fruits should be burnt at once to prevent diffusion of the 

 oonidia. Spraying uninjured fruit may save them from attack. 



Mom. PI Dm. 880; Cooke Hdbk. No. 1801. 



Mulberry-leaf Spot. 



Phleosjyora mori (Lev.), PI. XII. fig. 38. 



Mulberry leaves are sometimes marked by rather large irregular spots 

 or bleached tissue circumscribed with a definite border line of brown. The 

 spots themselves are pale, either dirty white or tinged with ochre. 

 Scattered over the upper surface of the spots numerous black dots 

 indicate the small globose receptacles sunk into the substance of the 

 leaf. 



Within these receptacles are produced the elongated cylindrical conidia, 

 or sporules, which are curved, rather obtuse at the ends, and divided 

 across by three septa, or occupied by four guttules, or nuclei, entirely 

 colourless, and at first growing from short sporophores, or pedicels 

 (40-50x4 fx). 



First observed in this country at Clevedon, and since then has been 

 found in several localities. At one time the theory was promulgated in 

 France that this disease of the leaves was the cause of " muscardine," or 

 silkworm disease, but for lack of evidence the theory soon gave way. 



Trees when once attacked continue to suffer year after year with 

 increasing energy. Cold weather appears to check it, but in warm 

 seasons it extends rapidly. 



The disease is known in France, Italy, Germany, Austria, and Russia. 



Sacc. Syll. iii. 3136 ; Grcvillea, vi. p. 72, xiv. 104 ; Gard. Chron. 

 Nov. 1*77. 



Mulberry-leaf Blight. 

 Ccrcospora moricola (Cooke), PI. XII. fig. 29. 



Nearly at the same time that the Mulberry spot appeared in this 

 country another disease was found affecting the leaves of the Mulberry 

 tree both in this country and in the United States. It belongs to a 

 genus of black moulds which are really very persistent in their attacks 

 and very troublesome to the cultivator, but not likely to be of so much 

 Importance to us as to countries where the leaves are required in con- 

 nection with the silkworm industry. 



The spots occur on both surfaces, and are orbicular, of a reddish- 

 bown Dolour. Upon these spots are produced tufts, or bundles, of short 

 olive threads, which burst through the cuticle and produce at the apex 

 of each thread a lon<( narrow spore, or conidium, which is three or four 

 septal*-, and narrowed towards one end (70x3 /<). 



No i cperinu Qts have been made to control this disease, as in its 

 present development it cannot affect the production of fruit. 



Sacc. Syll. iv. 2281 ; Grevillea, xii. p. 30. 



