jPROCEEDINGS OF 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 FilaricF. 
To confirm the opinion of these parasites attacking the larvae of insects, he in¬ 
stanced those genera, as Acilms^ Colyinheies^ and Fhryganea^ in which the larv^B 
are aquatic. Fhryganim 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 Filariss in larvce of any kind. Rudolphi had 
stated that he thought all the parasitic Filari(E were of the same genus : but he 
doubted this ; and even Rudolphi had marked one as “ genus doubtful.” The 
Filaria found in Phryganidee differed from those of Coleopiera. The species of 
the genera Ascaris and Filaria^ he thought would bear distributing into several 
other genera. The species found in Phryganidm appears intermediate betvv^een 
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 Bibliot/ieque Universelle 
there was an account of a Filaria found on a species of Gryllus. 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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