PROCEEDINGS OP THE BRITISH ASSOCIATION. 431 



petals of the Hyacinth contained no spiral vessels, when in fact they existed 

 there in great abundance. In the next place, it appeared to him that the author 

 had confounded cellular membrane and woody fibre with elementary membrane 

 and fibre. The analysis of the former was easily obtained, but that of the latter 

 must still be a desideratum. 



The Rev. F. W. Hope then read some " Remarks on Filaria, a Genus of 

 Parasite Worms, recorded as infesting Man and Insects." His object, he stated, 

 was to call the attention of the Section to this class of parasites, and to solicit 

 authentic information respecting them. He believed they first attacked insects 

 in their larval state, and grew with their growth. He thought one of the uses 

 of parasites might be to control the exuberance of species. He presented to the 

 meeting a table of forty genera, and several species of insects, infested by Filaria. 

 To confirm the opinion of these parasites attacking the larvse of insects, he in- 

 stanced those genera, as Acilius, Colymbetes, and Phryganea, in which the larvae 

 are aquatic. Phryganicn are frequently the subjects of these attacks, which could 

 not well take place after they had emerged from the pupa state. He had not, 

 however, succeeded in detecting Filarise in larvse of any kind. Rudolphi had 

 stated that he thought all the parasitic Filarice were of the same genus : but he 

 doubted this ; and even Rudolphi had marked one as " genus doubtful." The 

 Filaria found in Phryganidca differed from those of Coleoplera. The species of 

 the genera Ascaris and Filaria, he thought would bear distributing into several 

 other genera. The species found in Phryganidcn appears intermediate between 

 Gordius and Filaria. The author concluded by suggesting that the term Filaria 

 be restricted to the Filaria Medinensis (or Guinea- worm) and its congeners; while 

 several other sub-genera may be formed, to include the parasites infesting insects. 

 Mr. Duncan inquired if it was the opinion of Mr. Hope that each genus of 

 insects was attacked by its peculiar parasites ? It had been stated, at a former 

 meeting of the Association, that this might be one means of determining the 

 genus or species of animals ; and, if the parasites were constant, it would un- 

 doubtedly be a valuable means of diagnosis. — The President observed that he 

 had seen parasitic worms in the Arachnida ; and in the Bibliotheque Universelle 

 there was an account of a Filaria found on a species of Gryllns. The economy 

 of these animals is very curious : they may be dried, and brought to life again by 

 moisture at an indefinite period. They are common in the waters of clay soils, 

 and may probably be introduced into the system in the same manner as the Fas- 

 ciola, which produces the " rot " in sheep, and which exists in the water from 

 which the animals drink. — Mr. Hope replied that he believed each genus o* 

 insects had its distinct parasite, and he thought that even now he could tell to 

 what order an insect belonged by examining its parasitic invaders. 

 Mr. Bowman read a paper by Mr. Gardner, " On the Internal Structure of 



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