184 PROCEEDINGS OF THE 



disease to which the common house-fly appears subject, and 

 which is exhibited by a dilatation of the abdomen, and the 

 appearance of something like a fungus between the segments ; 

 Mr. MacLeay, at the Liverpool meeting, expressed his con- 

 viction that the disease was occasioned by, or was in itself, a 

 plant, at present undescribed, growing on the insect, and not 

 plethora, as had been suggested by Mr. Kirby ; Mr. MacLeay 

 considered it a highly interesting fact that we had now positive 

 evidence in each kingdom, the animal and vegetable, of indi- 

 viduals which lived parasitically on those of the other : plants 

 living on plants, animals on animals, and animals on plants, 

 had long been known to us ; but we had now, for the first time, 

 an instance of a plant living on an animal. In reply to Mr. 

 MacLeay's observations, Professor Lindley had remarked, that 

 a disease called " Muscadine," which had for many years 

 existed among the silkworms in the south of France, and 

 had occupied the attention of the Academie des Sciences, was 

 supposed to proceed from a parasitic plant ; he thought the 

 vegetable parasite of the fly was a species of Botrytis. Mr. 

 Westwood, after adverting to these observations, presented draw- 

 ings of the plant in question, which he considered to be very 

 similar to the Botiytis Bassiana, the supposed parasite of the 

 silkworm ; this Botrytis was said to consume the fatty parts 

 of the silkworm, and to leave the remainder transparent, and 

 brittle like glass : this, however, was not the case with that of 

 the fly. Mr. Shuckard observed that he has noticed many 

 genera of Diptera, and especially Scatophaga, attacked by the 

 same disease. The President said he had observed it also in 

 the Hymenopterous genus Diodontus. 



Mr. Saunders exhibited a small case of Indian insects. 



Mr. Westwood exhibited a turnip which had been attacked 

 by several large grubs; these had completely riddled the turnip 

 before the attack was perceptible exteriorly. Mr. Westwood 

 proceeded to detail the operations of these grubs, when Mr. 

 Yarrell observed that they were the larvae oi Agrotis Segetum, 

 whose ravages had been fully described. 



Mr. Sells read an elaborate diary of the numbers of the 

 larvai of the bots of Horses, which had been brought to him 

 during the past summer, stating the dates and daily numbers. 

 After he had finished this detail he remarked, that he con- 

 sidered Mr. Bracy Clark in error, in supposing that these 



