Section V. ANIMAL PARASITES AND ASSOCIATED DISEASES
CHAPTER XL
I. PARASITES OF THE CIRCULATORY AND LYMPHATIC SYSTEMS
FILARIASIS
History.— Our knowledge of this subject dates from the discovery by Demarquay, in 1863, of a larval nematode— microfilaria bancrofti (Plate X.) —in the milky fluid from a case of chylous dropsy of the tunica vaginalis. Later, in 1866, Wiicherer found the same organism in the urine of a number of cases of chyluria. In 1870 Lewis made a similar observation in India, and in 1872 discovered that the blood of man was the normal habitat of this larval parasite, which he named, accordingly, Filaria sanguinis hominis. Four years later Bancroft, in Brisbane (Queensland), discovered the adult form, and Cobbold named it Filaria bancrofti. Since that time the subject has rapidly expanded, and its great practical importance in tropical pathology is now recognized.
Nomenclature of the parasites.— I have pointed out that Lewis's microfilaria*[1] is not the only blood-worm in man, and that the human circulation is the habitat of the larvae of no fewer than five, possibly of six or even more, distinct species of filariæ. In consequence of this discovery, it was deemed advisable to modify the original name of Lewis's filaria. This I
- ↑ * The term microfilaria has been suggested by Le Dantec to designate the larval forms of the various nematodes whose young circulate in the blood. I adopt it as being a convenient expression.
