As many of the so-called free nematodes live in the slime of animals, Villot is of opinion that no very distinct line of demarcation can fairly be drawn between the parasitic and free species. This work, however, having dealt only with genuine parasites, I have purposely omitted any detailed account of the so-called free nematoids. I mention this lest it should be supposed that I had shown a studied neglect of the more or less remarkable labours of Bütschli, Bastian, Eberth, Linstow, Marion, Villot, Claus, De Man, Carter, and many others.
Bibliography (No. 60).—Bastian, H. C., “Monograph on the Anguillulidæ, or free Nematoids, marine, land, and freshwater, with description of 100 new species,” ‘Linnean Trans.’ for 1865, vol. xxv, p. 73.—Idem (see Bibliog. No. [2]).—Idem, “Free Nematoids,” being an article in the ‘Popular Science Review’ for 1868, vol. vii, p. 163.—Brady, G. S., ‘Monograph of the free and semiparasitic Copepoda,’ London, 1878.—Bütschli, O., “Untersuchungen ueber freilebende Nematoden und die Gattung Chætonotus,” ‘Sieb. und Köll. Zeitschrift,’ 1876.—Carter, H. J., “On a Bisexual Nematoid Worm which infests the common House-fly (Musca domestica),” ‘Ann. Nat. Hist.,’ 1861, and in the ‘Bombay Med. and Phys. Soc. Trans.,’ new series, 1860.—Claparède (see Panceri).—Claus, C., ‘Beobachtungen ueber d. Organis. und Fortpflanz. v. Leptodera appendiculata,’ 1869.—Cobbold, “Note on Insect Parasites,” in ‘Rep. of Entomological Club,’ in the ‘Midland Naturalist,’ March, 1878, p. 80.—Cole, W., “Remarks on a Parasite of Humble Bees,” in ‘Journal of the Quekett Microscopical Club,’ 1875.—Dufour, L., “Sphærularia,” ‘Ann. des Sci. Nat.,’ 1836.—Dujardin, “On Mermis,” ‘Ann. des Sci. Nat.,’ 2e sér., tom. 18, p. 129.—Eberth (see Bibliog. No. [2]).—Garner, R., “Note on a Distoma,” in his paper ‘On the Lamellibranchiate Conchifera,’ ‘Trans. Zool. Soc.,’ 1841.—Ghaleb, O., “Observations and Experiments on the Migrations of Filaria rhytipleurites, a Parasite of Cockroaches and Rats,” ‘Comptes Rendus,’ July 8, 1878, and ‘Ann. Nat. Hist.,’ Aug., 1878.—Idem, “Note sur l’anat. et les migrations de deux Nématoides parasites, le Pæcilogaster blatticola et Fil. rhytipl.,” Paris, 1876 (quoted by O. von Linstow).—Giard, M. A., “On the parasitic Isopoda of the genus Entoniscus (infesting Crustacea),” from ‘Comptes Rendus,’ Aug., 1878, in ‘Ann. Nat. Hist.,’ Otc., 1878.—Idem, “On the Orthonectida, parasitic on Echinodermata and Turbellaria (Rhopalura),” ‘Ann. Nat. Hist.,’ Feb., 1878.—Grube, A., “On Cyclops as a new Cestoid-bearing Host,” from ‘Zoologisch. Anzeiger,’ Bd. i, s. 74, in ‘Journ. Royal Microsc. Soc.,’ Nov., 1878, p. 254.—Hunter, J., “Filaria of the Bee,” in ‘Catal. (by Owen) of the contents of the Mus. Royal Coll. Surg.,’ part iv, fasc. i, p. 37, 1830.—Kynston, “Worms attached to a Grasshopper,” ‘Proc. Ashm. Soc.,’ in ‘Corbyn’s India Review,’ and in ‘Journ. of Foreign Sci.,’ 1837, p. 172.—Lima, J. F. da S., “Remarks on the Filaria medinensis or Guinea-worm; on the occurrence of this parasite in the Province of Bahia; and on its entrance into the human body by drinking water;” trans. from the Portuguese by Dr J. L. Paterson, and pub. in the ‘Veterinarian’ for Feb., 1879 et seq.—Linstow, “Helminthologische Beobachtungen,” in ‘Archiv für Naturgeschichte,’ 1876.—Lubbock, Sir J., “On Sphærularia bombi,” ‘Nat. Hist. Rev.,’ 1861.—Idem, “Notes,” &c., ibid., 1864, p. 265.—Mason, J. W., “Note on the Geographical Distribution of the Temnocephala chilensis (parasitic upon a freshwater crayfish, Paranephrops setosus, in New Zealand),” ‘Annals Nat. Hist.,’ 1875, p. 336.—Marion, A. F., ‘Revision des Nématodes (&c.),’ Marseilles.—Maund, B., “A description of Filaria forficulæ,” ‘Rep. Proc. Linn. Soc.,’ in ‘Zool. Journ.,’ 1832–34, p. 263.—Meissner (see Thomson).—Owen, R. (see Hunter).—Pagenstecher (see Bibl. No. [58]).—Panceri, P. (e di E. D. Claparède), “Nota sopra une alciopide parassito dell Cydippe densa,” ‘Mem. della Soc. Ital. di Sci. Nat.,’ 1867.—Sars, “Intestinal Worm in an Acaleph.,” from ‘Wiegmann’s Archiv,’ in ‘Ann. Nat. Hist.,’ 1845.—Siebold, C. J. von, in ‘Wiegmann’s Arch.,’ 1835.—Idem, in ‘Ray Soc. Rep.’ (by Busk), 1847.—Idem, “Worms,” &c., ibid., p. 503, 1847.—Idem, “Report on Helminthology, and on the Nemertinæ” (trans. by W. B. Macdonald, in ‘Ray Soc. Rep. on Zool.,’ 1842, p. 280), Edinburgh, 1845.—Idem (see Thomson).—Thomson, A. (for review of the writings of Meissner, Von Siebold, and others, respecting the development of Mermis, Gordius, &c., see the classical and elaborate art. “Ovum”), in ‘Supp. to Todd’s Cyclop.,’ 1859.—Vogt, C., “On some Inhabitants (Cercariæ) of the Fresh-water Mussels,” from ‘Ann. des Sci. Nat.,’ in ‘Ann. Nat. Hist.,’ 1850.—Whitman, C. O., “The Embryology of Clepsine (with valuable Bibliography),” ‘Quart. Journ. Micr. Sci.,’ July, 1878.
Appendix.—The memoirs announced by Dr T. R. Lewis in the January issue of the ‘Microscopical Journal,’ and referred to at the close of my account of Filaria Bancrofti, having appeared, I fulfil the promise previously made (p. [202]). In the few lines at my disposal I may observe that the beautiful brochure (quoted below) supplies fuller details of the results already announced by Lewis in the ‘Proceedings of the Asiatic Society of Bengal.’ In respect of the nematoid hæmatozoa, the memoir is chiefly important as confirming Manson’s observations regarding the changes undergone by the Filariæ that have been transferred to the stomach of the mosquito, and especially also, as advancing some novel facts in reference to the occurrence of bird’s blood-corpuscles, associated with embryonic nematoids, in the same viscus of the insect. The worms are regarded by Lewis as transferred avian hæmatozoa, a view which gains strength by their comparison with the similar larvæ which he had detected in the blood of Indian crows (Corvus splendens). In Egypt, as Sonsino had himself informed me by letter, similar hæmatozoa are to be found in crows, and avian filariæ of this kind were long previously described, as Lewis and Sonsino point out, by Borell, Herbert, Schmidt, and Virchow. Facts of this order undoubtedly complicate matters, and suggest that extreme measure of caution in drawing conclusions, which Lewis himself everywhere displays.
Respecting the final changes undergone by the mosquito-filariæ before their re-entrance into the human body, Lewis does not appear to have gone further than Dr Manson. By rupturing the body of the most advanced larvæ, Lewis readily recognised the œsophagus and intestine, but he remarks, significantly, “I have not been able to distinguish any other differentiated viscus in any of the specimens, and certainly, nothing suggestive of differentiation of sex” (p. 83). In an earlier part of the memoir Dr Lewis takes objection to my view that the urinary nematoids found by me in a case of Bilharzia are genetically related to Filaria sanguinis hominis. His distinguished coadjutor, Dr D. Cunningham, also denies the possibility of such relationship. No doubt, if the urinary maternal worm was really oviparous my view is untenable; but the proved presence of imperfectly formed ovarian ova, in which no trace of embryonic formation was discernible, has forced upon me the conviction that prolapsus and rupture of the uterine tubes of the parent worm had occurred, and that their rupture had occasioned the escape 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 correction” 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 filariæ 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 filariæ. In one of the captured insects Bancroft himself detected forty-five filariæ. The cases have been forwarded 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 l’idée qui existe chez nous, où le peuple croit et affirme que—quand une personne qui souffrait auparavant d’erysipèle a un abcès cela la préserve de nouveaux accès. La raison ne sera-t-elle pas que dans ce cas, avec l’ouverture de l’abcès, le ver sort? Je le crois. Ces faits viennent démontrer que la cause de la maladie est le ver. Cependant nous avons ici à Bahia plusieurs confrères qui ne le croient point! Et à Rio-de-Janeiro aussi il y en a, peut-être davantage(!).” I will only add that Dr Araujo deceives himself if he imagines that the full etiological significance of parasites in relation to disease will receive general professional recognition for many years to come.
Supplement to Bibliography No. [23], p. 202 (with emendations).—Araujo, ‘Memoria sobre a Filariose ou a molestia produsida por uma nova especie de parasita cutaneo,’ Bahia, 1875.—Idem, “Da filariose,” ‘Globo,’ Jornal do Rio de Janeiro, 1876, e ‘Revista Medica do Rio de Janeiro,’ 1876, anno 3o, No. 2, 15 de Julho, p. 107.—Idem, “Caso de chyluria, elephancia do escrôto, escrôto lymphatico, craw-craw e erysipela em um mesmo individuo; descobrimento da Wuchereria filaria na lympha do escrôto. Tratamento pela electricidade com excellentes resultados,” ‘Gaz. Med. da Bahia,’ 2a serie, vol. 2o, No. 11, Nov. de 1876.—Idem, “A Filaria Wuchereri no sangue,” ‘Gaz. Med. da Bahia,’ Mar. de 1878, p. 106, e seguintes.—Idem, “A muriçoca e as filarias Wuchereri,” ‘Gaz. Med. da Bahia,’ Setembro de 1878.—Idem, “La Fil. immitis,” &c., Transl. of Mem. (l. c., Bibl., No. [45]) in ‘Lyon Médical,’ Nov., 1878, p. 319 et 363.—Bancroft, “Instance of a European having taken leprosy in Queensland,” in a letter to myself; see “Case from Bancroft,” quoted at p. 203.—Chassaniol, A. (et F. Guyot), “Hématurie graisseuse ou chyleuse,” in their “Notes de Géographie Méd. recueillies à Taïti,” in ‘Archives de Méd. Navale,’ Jan., 1878, p. 65.—Cobbold, “Worms in the Heart of Dogs,” letter in the ‘Lancet,’ April 5, 1879, p. 498.—Coles, “On Lymph-scrotum,” ‘Brit. Med. Journ.,’ March 9, 1878.—Fayrer, Sir J., “Lecture on Elephantiasis Arabum,” in the ‘Lancet,’ March 29, 1879, p. 433.—Idem, ‘Report of Pathol. Soc.,’ ‘Lancet,’ Feb. 22, 1879, p. 267.—Idem, ‘Rep. of Epidemiological Soc.,’ ibid., p. 269.—Idem, ‘Letter on Filaria;’ see Hoysted.—Ghaleb, O. (with P. Pouquier), “On Filaria hæmatica,” from ‘Comptes Rendus,’ Feb. 5, 1877, in ‘Annals Nat. Hist.,’ April, 1877.—Hoysted, J., “Notes of a Case of Filaria sanguinis in a Dog;” see Bibliog. No. [49], p. 311.—Lewis, T. R., ‘The Microscopic Organisms found in the Blood of Man and Animals, and their relation to Disease,’ Calcutta, 1879.—Idem, “The Hæmatozoa of Man (excerpt of the above),” ‘Quart. Journ. of Microsc. Sci.,’ April, p. 245 (both from ‘14th Ann. Rep. of the San. Commissioner with the Govt. of India’).—Makuna, ‘Letter respecting Fil. sang. hom. in Chyluria’ (l. c., Bibliog. No. 23).