DISEASES OF INSECTS. 237 
intestinal worms which Rudolph has denominated En- 
tozoa nematoidea, and Lamarck Vers rigidules*. To 
this tribe belong the Gordius of Linne and the Filaria 
of modern zoologists, which from the experiments and 
observations of De Geer, Dr. Matthey, &c. appear to 
have been too hastily separated, being really congene- 
rous, and living indifferently in water and in the intes- 
tines of insects and other animals 5 . To this <r e nus 
belong the guinea- worm {Gordius medinensis% the 
Furia infernalis, and several others that are found in 
various vertebrate animals. These little worms have 
been discovered in insects of almost every Order ; and 
their attack generally produces the death of the animal, 
though they appear not to devour those parts that are 
essential to life d . I once took a specimen of Pcecilus 
azureus, and upon immersing it in boiling water I was 
surprised to see what at first I mistook for an intestine, 
thrust itself forth ; but upon a nearer inspection, to my 
great surprise I found it was one of these worms, thicker 
than a horse-hair and of a brown colour. Mr. W. S. 
MacLeay also once found one in Abax Striola. It still 
remains in my specimen, making it appear as if it had a 
long tail. De Geer long ago found these worms in 
grasshoppers d ; but Dr. Matthey has given the fullest 
account of one which infested Acrida viridissima. A 
friend of his noticing one of these insects which had not 
strength enough to leap and could scarcely even walk, 
a Lamarck Anim. sans Vert. hi. 196. 
b De Geer ii. 554—. Pictet BMiotheq. Univers. num. ult. 
c The existence of this animal has been satisfactorily ascertained 
by M. de Blainville, who had a specimen, extracted from a human 
body, sent him by M. Girard, a surgeon of Guadaloupe. 
1 De Geer ii. 555. 
