Gelehrte Gesellschaften. 91 



Canestrini and Fanzago, of Padua , in 1876, under the generic 

 name of Chizonemus (Atti. Soc. Veneto-Trentina di Sei. Nat. , vol. V., 

 fasc. I). The authors subsequently discovered that the name had been 

 used by Cuvier for a genus of fishes, and accordingly changed tbe 

 name to Tarsonemus (ibid.). Dr. Krämer, of Schleusingen, sub- 

 sequently found the sanie creature , and described it independently 

 under the name of Dendroptus (Archiv, für Naturgesch., 1876, p. 197). 



The species appears to be identical with Tarsonemus Buxi, which 

 Professor Canestrini found in 1884 in great quantities on the Box 

 trees at Venice and Padua, and which he says nearly destroyed the 

 foliage of the trees of Buxus sempervirens in the Botanic Gardens at 

 Padua. Professor Canestrini states that the mite burrows in bet- 

 ween the upper and lovver cuticles of the leaf, and eats out the whole 

 of the parenchyma. 



In the instances of the Mormodes leaves the injury appears to 

 have been chiefly affected from the exterior, and the leaf to bave 

 swollen after the wound, so as to form a gall-like body. The Italian 

 Professor states that the Acari most readily attack leaves which have 

 already been injured by insects. I did not find any trace of this with 

 the Mormodes leaves. It appears to me that the original injury to 

 these plants had probably been e£fected while the leaves were quite 

 young, but showed more as they grew older. 



I found a species of the same genus in the Midland Counties 

 of England last year, in considerable numbers, burrowing under the 

 cuticle of the common Burdock. 



Sclerotioids of Potato Disease. 



Communications on this subject were read from Mr. G reen w ood - 

 Pim, Prof. Trail, and Mr. Wilson. A further communication, with 

 sketch, was sent by Mr. Worthington Smith, but by some mishap 

 did not arrive tili after the close of the meeting; but to make the 

 record complete , Mr. Smith 's communication, of which a copy was 

 also forwarded to us with the woodcut , is printed in another i olumn. 

 Mr. Pim says that he has seen nothing to confirm Mr, Murray 's 

 contention that the protoplasm is outside the bodies. The „plasm" 

 seems to correspond exactly with the original body in size and shape. 

 Mr. Pim, however , doubts whether the bodies have any connection 

 with the disease. 



Professor Trail writes: 



It is satisfactory to find that Mr. Murray no longer adheres, 

 as in the report published in the Journal of Botany in December, 

 1883, to the view that no trace of a plasmodium was left after the 

 action of nitric acid ; but that, on the contrary, the protoplasmic sub- 

 stance found by others to remain after isolated ,sclerotiets' were 

 treated with nitric acid was found by him without difficulty and 

 stained easily. But he continues: — ,1 failed entirely and absolutely 

 to find the smallest evidence that the substance was contained in the 

 body. The statement that it is so contained is the merest assertion. 

 Obviously, if it were the case, it would suit Mr. Wilson's theory. 



