APPENDIX. 487 



of ova in various stages of growth. As free embryos were 

 also detected, the adult worm was probably viviparous. There 

 is an error in the representation of the oval-shaped ovum given 

 in the figure (p. 183). I retain drawings of eighteen perfect 

 nematoid ova from the Bilharzia case, and not one of these 

 shows any double contour of the chorional envelope. In 

 the case of the imperfect ova, the double contour is obviously 

 due to the close apposition of the yelk-membrane to the shell- 

 membrane, there being no true shell. As regards " a correc- 

 tion " which Lewis makes in respect of the question of priority 

 of description of the mature Filaria sanguinis hominis I can only 

 find space to state frankly, that Lewis is perfectly correct. 

 The error was quite unintentional on my part. The adult worm 

 was first discovered by Bancroft, and upon the strength of his 

 admittedly scanty record I named the worm Filaria Bancrofti. 

 In the matter of supplying a proper diagnosis and an anatomical 

 description I was completely anticipated by Lewis. No doubt, 

 Dr Bancroft could have furnished a fuller description of the 

 parasite, had he desired to do so, but here is what he says in 

 the letter addressed to me from Melbourne on the 20th of 

 April, 1877 : " I thought it better to send you this account of 

 filarise than to publish it direct, as you so kindly set me on the 

 track of the investigation." Here I feel constrained to remark 

 that few, if any, of my many correspondents in helminthology, 

 have displayed more engaging candour. Whilst actually writing 

 this Appendix (April 15th, 1879) I have received a new record 

 of filarious cases from Dr Bancroft, who also sends me some 

 mosquitoes captured by a victimised patient whose blood 

 swarmed with filariee. In one of the captured insects Bancroft 

 himself detected forty-five filarise. The cases have been for- 

 warded to the ' Lancet ' for publication. Lastly, in reference 

 to the closing paragraph of Bancroft's previous letter to me 

 (pub. in the 'Lancet,' Feb. 1st), I have received the following 

 interesting commentary at the hands of Dr Silva Araujo, 

 whose letter is dated from Bahia, March 3rd, 1879 : " Je dois 

 vous communiquer que ce fait vient confirmer 1'idee qui existe 

 chez nous, ou le peuple croit et affirme que qnand une per- 

 sonne qui souffrait auparavant d'erysipele a un abces cela la 

 preserve de nouveaux acces. La raison ne sera-t-elle pas que 

 dans ce cas, avec Touverture de 1'abces, le ver sort ? Je le 

 crois. Ces faits viennent demontrer que la cause de la maladie 

 est le ver. Cependant nous avons ici a Bahia plusieurs con- 



