[Footnote 11: _Occlusion and Dilatation of Lymph-Channels_, by Samuel C. Busey: A series of papers reprinted for private distribution from the _New Orleans Medical and Surgical Journal_, from Nov., 1876, to March 1878.] {118} If it be acknowledged, then, that in chyluria some direct communication must exist between the lymphatic and urinary systems, how is this communication brought about? Various causes have been supposed at different times to be responsible for this condition, among them traumatism in its various modes of occurrence, such as being thrown from a horse. Mental shock has also been held responsible. So, also, syphilis and hereditary tendency. But most cases still remained unaccounted for when, on August 4, 1866, Wücherer first detected in the chylous urine of a woman in the Misericordia Hospital at Bahia an unknown worm. In 1872 it was announced that Timothy R. Lewis had found in the blood, and also in the urine, of a person suffering with chyluria in Calcutta, a delicate thread-like worm about 1/70 of an inch long and 1/3500 of an inch wide. This observation was confirmed by Palmer and Charles. Lewis named it Filaria sanguinis hominis. Since then the filaria has been found in the blood and urine of many cases. Lewis found six in a single drop of blood from the ear, and estimated 700,000 as approximately correct for the whole body. But Mackenzie calculated that there were in the blood of his patient from 36,000,000 to 40,000,000 embryo filariæ. These minute nematodes, discovered by Wücherer and Lewis, proved to be, as was indeed early suspected, the larvæ of a larger filaria which was discovered by Bancroft of Brisbane, Queensland, Australia, in December, 1876, first in a lymphatic abscess in the arm, and afterward in the fluid of hydrocele of persons infested with the smaller worm. The parent worm is about the thickness of a human hair and three or four inches long. It was named, by Cobbold, Filaria Bancrofti. Lewis himself found, in August following, a male and female of the parent worm, in a scrotum infiltrated with chylous fluid, in a case of elephantiasis. The female contained ova with embryos precisely like those found in the blood and urine. The worms are viviparous, but abortions seem frequent, ova being frequently discharged unhatched. It has been rendered highly probable, by the researches, first, of Manson in China, and later of Lewis in India and Sonsino in Egypt, that the filaria in its fully-developed form is introduced into the stomach and intestines of man with water. Thence it makes its way into the blood and lacteal system, where it reproduces the embryo filariæ. These embryonic or larval filariæ are taken from the human blood by a mosquito, in the body of which it undergoes further development, after which the perfect Filaria Bancrofti is deposited in water, through which it again reaches the stomach of man, and thus the disease is perpetuated.