190 PARASITES OF MAN 



each showed a double skin, the outer envelope in the more 

 advanced specimens leaving clear spaces at either end of the 

 body, resulting from commencing ecdysis. I saw no trace of 

 intestinal tube, but a central line of condensation marked an 

 early differentiation of the somatic granular contents. The less 

 advanced embryos were mostly enclosed in a chorional envelope, 

 the smallest free embryos measuring only ~" in length by ^" 

 in breadth. These had no double contour. The ova, whose 

 yolk- contents were still in various stages of cleavage, gave an 

 average long diameter of g~ to ^5 of an inch. 



Such are the facts I made out, and they enabled me to 

 amend the characters of the species. 



As regards nomenclature, I associated Dr Bancroft's name 

 with the sexually- mature worm as being in harmony with the 

 binomial method and little calculated to mislead ; moreover, it 

 helped to fix both the source and date of the discovery (Bris- 

 bane, Dec. 21st, 1876). The use of this nomenclature detracts 

 nothing from the high merits of Lewis, who first named the 

 immature worm Filaria sanguinis hominis. As it now turns 

 out, both Dr Salisbury and myself had previously been made 

 acquainted with the young of Filaria Bancrofti ; but it was 

 reserved for Lewis to discover the haematozoal character of the 

 embryos of this worm, and actually to take them from the 

 blood. It was a singular circumstance, that when I was 

 engaged in treating my little African patient for trematode 

 haematozoa, it never once occurred to me that the numerous 

 nematoid embryos mixed with the Bilharzia ova were haema- 

 tozoal. As before remarked, it was alleged that my patient 

 had passed worms two or three inches long by the urethra. I 

 therefore concluded that these were the parents of the eggs 

 and embryos, and that all of them were urinary. The infer- 

 ence was wrong, but it has instructively shown how near one 

 may go towards a great discovery without really making it. 

 As regards the larvae, notwithstanding some slight differences 

 in regard to size and so forth, I have little hesitation in saying 

 that all the embryo forms severally described by Salisbury, by 

 myself, by Lewis, Sonsino, Wucherer, Crevaux and Corre, 

 Silva Lima, Bancroft, Hanson, and others, are referable to one 

 and the same species. 



Into the clinical bearings of this subject it is impossible for 

 me to enter at any length, but I may remark that these para- 

 sites appear to be associated with, if not actually the cause of, 



