OBSERVATIONS ON PILARIS. 63 



have entirely resulted from the hours of the day selected or acci- 

 dentally employed for the blood-examinations. He incidentally 

 alludes, also, to the common eye worm of horses (Filaria papillosd) 

 and some other helminthological points of general interest. It is 

 very curious to observe Dr. Somerville's remarks respecting a case 

 of lymph-scrotum, which he examined in company with Dr. Patrick 

 Hanson's brother (since deceased). The negative results of his 

 search for FUarice is now readily explained. 



Dr. Bancroft's brief communication deals with facts that verify 

 his original opinion that the peculiar growth which he has termed 

 Helminthoma elastica is really due to the presence of Filaria 

 sanguinis hominis. Of more interest, however, is the circumstance 

 that he has ascertained from actual observation that the common 

 louse of the dog (Trichodectes latus) is the intermediate bearer of 

 the larv£e of Filaria immitis. It will be remembered that iNIelnikow 

 long ago demonstrated by experiment the intermediary functions of 

 the louse in respect of the larvse of a cestode (Tcenia cucumerina) ; 

 and it is therefore not a little curious that this insect should play a 

 similar i^ole in respect of a parasitic nematode. 



Dr. J. F. da tSilva Lima's letter specially refers to a singular 

 affection which some persons appear to have associated with 

 elephantiasis. He alludes to a paper by himself on Filaria 

 medinensis, a translation which (from the Portuguese, by Dr. Pater- 

 son) I published in the Veterinarian in the spring of 1879.^ 

 Dr. Lima encloses a paper by Dr. Paterson, which must be regarded 

 as the sequel to his interesting paper, entitled " Facts in Filariasis," 

 which also appeared in the Veterinarian (June, 1879). 



As Dr. Paterson's recent memoir, however, is of considerable 

 length and relates to a point respecting which there ought not, in 

 my opinion, to have been any controversy at all, I shall only repro- 

 duce a portion of it. The memoir deals exclusively with the nature 

 of the involucrum of Filaria sanguinis hominis. Dr. Paterson 

 appears to have thought that the envelope surrounding the micro- 

 scopic i^?7a?'/fF is no genuine worm structure, but a merely adventitious 

 layer of coagulated fibrin. Havmg published this view. Dr. 

 Magalhaes, of Rio de Janeiro — from whom I have also received 



* " Remarks on the Filaria medinensis or Guinea worm ; on the occur- 

 rence of this parasite endemicallj in the province of Bahia ; on its 

 entrance into the human body by drinking-water.'' — The Veterinarian, 

 Feb.-March, 1879. 



