296 THE ANIMAL PARASITES OF MAN 



Pennatus reared from the larva and fed on infected persons. This 

 seems to prove that Filaria perstans in its proper intermediary 

 host, like Filaria bancrofti, develops between the thoracic muscles. 

 Dr. Christy suggests that the true intermediary host of Filaria 

 perstans is Ornithodoros monbata, 1 a tick of the sub-family Argasince. 

 However, he gives no evidence in support of this view, which is 

 contradicted by facts of geographical distribution. I am inclined 

 to think that the intermediary host of F. perstans is to be found 

 amongst, the blood-sucking flies. 



At one time F. perstans was incriminated as a possible factor 

 in the etiology of sleeping sickness. Recent researches have 

 proved that it has no causal connection with the disease. F. 

 perstans seems to have no pathological importance. The presence 

 of the adult parasites in the mesentery appears to cause no harm 

 to the host. L. W. S.] 



LITERATURE. 



O'NEIL. On the Pres. of a Filaria in "Craw-craw." (The Lancet, 1875, i., 



p. 265.) 



MANSON, P. L. c. 



FIRKET, C. M. Filariose du sang chez les negres du Congo. (Bull. Ac. roy, 



Med. de Belg., 1895, 4 Ser., ix., Ref. in C. f. B., P. u. Inf. [i], xix., 



p. 791.) 



HENRY. Rem. on Filaria. (Proc. Ac. Nat. Sc., Philadelphia, 1896, p. 271.) 



BRUALT, J. Note sur le Craw-craw. (Ann. Dermatol., Paris, 1899, p. 226.) 



6. Filaria demarquayi, Manson, 1895. 



Of this form also we know only the larvae circulating in the 

 peripheral blood. They are found in the blood night and day, 

 are provided with a sheath, but are only half the length of 

 the larvae of Filaria bancrofti. They have been observed in blood 

 preparations from natives of the Island of St. Vincent (Lesser 

 Antilles, West Indies). The same species is also supposed to occur 

 in Brazil and Africa (Niger). 



{Filaria demarquayi was discovered by Sir Patrick Manson in 

 1895 in blood films from natives of St. Vincent, West Indies. 

 Manson found the larval form of this filaria in ten out of 152 

 slides received from Dr. Newsan. 



The larva of Filaria demarquayi measures, according to Dr. 

 G. C. Low, o'2 mm. in length by 0*005 mm. in breadth ; it is 

 sharp-tailed, and has no sheath. Its movements are very active, 

 and the absence of a sheath enables it to glide along freely all 



1 [Professor Neumann informs me the correct name for this tick is Ornithodoros 

 savignyi (Audouin). The specimens received from Uganda all belong to Neumann's 

 variety caeca. ( Vide Second Report Eco. Zool. p, 113, 1904. Theobald). F.V.T.] 



