ANnTHKR PKAHI PKST 



ANOTHER PEACH PEST. 

 By M. C. Cooke, M.A., LL.D., A.L.S., F.R.H.S., V.M.H. 



We have lately (August 1907) received for examination some ripe peaches 

 which were suffering from a presumably new parasitic disease. A brief 

 examination was sufficient to remind us of a record of a like nature by the 

 Rev. M. J. Berkeley mere than forty years ago. Turning to this we were 

 soon convinced that the same disease was under our hands. The record 

 is in the " Gardeners' Chronicle " of October 1804, page 938, with a 

 woodcut, and the account is mainly as follows : — " We have met in the 

 garden of Sir Hugh Williams, in Wales, with a disease confined to a 

 single variety of peach, the Barrington, produced by a mould which we 

 have never seen before. 



" Shallow pits, about half an inch in diameter, appear on the surface 

 of the fruit, the centre of which is occupied by a dark mould bearing a 

 profusion of spores. The mycelium penetrates deeply into the fruit, 

 which, if not gathered in gcod time, beccmes useless. The mycelium 

 consists of more or less waved, articulated threads, which give off 

 here and there stouter erect flocci with shorter joints, branched slightly 

 above, and producing at the tip of each joint a large spore. The spores 

 are at first oblong and pale, showing one or two transverse septa. These 

 rapidly acquire a dark tint, elongate, become more or less linear, and 

 consist of from seven to eleven swollen divisions, of which the terminal 

 one is mostly apiculate. Each division contains a few minute oil 

 globules (the length varies from 40 to 00 ram.). 



" After the spores have fallen they frequently split in the centre and 

 give out a globular body, which is in all probability reproductive. The 

 mould apparently belongs to the genus Macrosporium, and may be named 

 M. rhabdifcrum. 11 



Thus much for the original account. The species was recorded in 

 "Cooke's Handbook" in 1871 under the name of Helminthosporium 

 rJuibdiferum, but we have failed to discover any specimen or any record 

 of its appearance since 1804, and began to look upon it so much in the 

 light of a myth that it was excluded from our " Pests of the Fruit 

 Garden," recently published by the Royal Horticultural Society. 



After more than forty years this same mould reappears, on the same 

 host, answering in every particular to the original description, and long 

 after it had become forgotten, and without a single record of its appearance 

 in this country or any other during the interval. 



Technically it must be stated that it is not a species of Marrospor'unn 

 at all, for the spores are not muriform ; nor is it Helminthosporium, for 

 the mycelium is delicate and uncoloured, and, moreover, there are no 

 dark or carbonised sterile flocci, and the mature spores are only a pale 



