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 genus 

 belong the guinea- worm (Gordius medinensis c \ 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. iii. 196. 



b De Geer ii. 554. Pictet Bibliotheq. Univers. num. ult. 



e 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. 



d De Geer ii, 555. 



