REVIEW — TROPICAL MEDICINE, ETC. 73 



the filaria from the mosquito to the dog, and has devised ingenious experiments for his Filariasis— 

 preliminary investigations. continued 



Smith^ has recorded from Sierra Leone the presence of two motile worms, apparently 

 nematoids, and resembling developing filaria embryos, in the thorax of a mosquito, which 

 appeared to be a non-blood sucker. This latter fact, however, required confirmation, and I 

 can find no further reference to the subject. 



Observations by Billet'-* appear to show a more or less close genetic relationship 

 between F. loa and F. dinnia, while an interesting case of F. loa infection is described by 

 Livon and Penaud,^* of Marseilles, wherein the microfilaria were found in the blood, urine 

 and saliva, and where there was a marked eosinophilia (55 to 70 per cent.). 



Ward has studied F. loa in North America. He mentions all the cases on record and 

 gives a very full and complete bibliography. 



The geographical distribution of F. loa is given and the statement made that the West 

 Coast of Africa is the proper home of the parasite. Strong recent evidence of the relation 

 of the parasite to Calabar swellings is cited. Ziemann is quoted as finding the embryos 

 in the swellings, but he believes that the latter are due to F. perstans, which he regards 

 as the embryonic F. loa, while F. din ma (he says) does not differ from F. lancrofti. 



Ward suggests that the swellings may be due to the discharge of waste materials of a 

 toxic nature. 



Several new facts have accumulated regarding filariasis in animals. These will be 

 found detailed under the heading "Veterinary Diseases" (page 217^. 



Nuttall* has publishel notes for the preservation of filaria intended to be sent for 

 identification or study. These are as follows :— 



Embkyos in the Blood 



1. Drop blood in a solution of 1 in 4000 perchloride of mercury in 8 per cent, saline. Mis by shaking, cork 

 and send without more ado. 



2. Drop blood into solution of iodine added to 8 per cent, saline, in quantity sufficient to give the saline a 

 pale sherry colour. Mix, cork and send. 



3. Drop blood into 10 per cent, boiling formalin solution, allow sedimentation to take place, then decant and 

 preserve in 5 per cent, formalin. 



4. Make blood smears on cover glasses, dry, pack them back to back, surround with thin paper (paraffined 

 better), put into smaU box into which paraffin, melting at not too high a temperature, say 50' to 60° C, has been 

 poured. Now pour in fresh melted paraffin so that the cover glasses lie in a block of paraffin. 



Note. — I have devised this method in the hope that it will work with films collected in the tropics, excluding 

 their growing mouldy and altering with regard to stains. 



Adult Pilable 



1. Place worms in saturated perchloride of mercury for 24 hours, then rinse with water for 30 minutes and 

 place in 70 per cent, spirit to which a little iodine has been added, so as to give it a sherry colour. Cork and 

 send. 



2. Place worms in dish, pour on boiling s.atuiated perchloride, rinse as before and store in iodinised 70 per 

 cent, alcohol. 



3. Drop worms direct into 4 per cent, formalin in 8 per cent, saline ; cork and send. 

 The different methods can be used according to the convenience of the worker. 



Low' gives the following method for making permanent preparations of filarial embryos. 

 Spread a large drop of blood as a film on a slide and allow to dry. Place in water till all 

 the red colour of the blood disappears and then apply a few drops of fuchsin, methylene blue 

 or hsematoxylin for a few minutes. Wash again in water, dry and mount in Canada balsam. 



O'Brien^ mentions two cases in which atoxyl, given intravenously, caused the embryos 

 of F. nocturna to disappear from the blood. He administered from 5 to 40 minims of a 

 5 per cent, solution, continuing the treatment in one instance for about two months. 



' Smith, F. (May 1st, 1905), " The Development of Filarise in the Mosquito." Journal of Tropical Medicine, 

 p. 140, Vol. VIII. 



" Billet, A., C. K. Soc. Biol, t. LXI., p. 507. 



" Livon, J., and PSnaud, December 1st, 1906, C. R. Soc. Biol. 



* Nuttall, Q. H. F. (October, 1904), "Directions for Preserving Filariae." Indian Medical Oazette, y. 391, 

 Vol. XXXIX. 



" Low, Q. C. (February 16th, 1903), " Method of Mounting Specimens of Bilharzia Eggs, Filarial Embryos, 

 and Small Worms of Any Kind." Journal of Tropical Medicine, p. 67, Vol. V. 



' O'Brien, R. A. (May 15th, 1908), " The Administration of Atoxyl Endovenously in Filariasis." Journal of 

 Tropical Medicine and Hygiene. 



• Article not consulted in the original. 



