e of the _filaria Bancrofti_ in the vessels, and is observed
chiefly in the groin, spermatic cord, and scrotum of persons who have
lived in the tropics.

_Filarial disease in the lymphatics of the groin_ appears as a soft,
doughy swelling, varying in size from a walnut to a cocoa-nut; it may
partly disappear on pressure and when the patient lies down.

The patient gives a history of feverish attacks of the nature of
lymphangitis during which the swelling becomes painful and tender. These
attacks may show a remarkable periodicity, and each may be followed by
an increase in the size of the swelling, which may extend along the
inguinal canal into the abdomen, or down the spermatic cord into the
scrotum. On dissection, the swelling is found to be made up of dilated,
tortuous, and thickened lymph vessels in which the parent worm is
sometimes found, and of greatly enlarged lymph glands which have
undergone fibrosis, with giant-cell formation and eosinophile
aggregations. The fluid in the dilated vessels is either clear or
turbid, in the latter case resembling chyle. The affection is frequently
bilateral, and may be associated with lymph scrotum, with elephantiasis,
and with chyluria.

The _diagnosis_ is to be made from such other swellings in the groin as
hernia, lipoma, or cystic pouching of the great saphenous vein. It is
confirmed by finding the recently dead or dying worms in the inflamed
lymph glands.

_Treatment._--When the disease is limited to the groin or scrotum,
excision may bring about a permanent cure, but it may result in the
formation of lymphatic sinuses and only afford temporary relief.

#Lymphangioma.#--A lymphangioma is a swelling composed of a series of
cavities and channels filled with lymph and freely communicating with
one another. The cavities result either from the new formation of lymph
spaces or vessels, or from the dilatation of those which already exist;
their walls are composed of fibro-areolar tissue lined by endothelium
and strengthened by non-striped muscle. They are rarely provided with a
definite capsule, and frequently send prolongations of their substance
between and into muscles and other structures in their vicinity. They
are of congenital origin and usually make their appearance at or shortly
after birth. When the tumour is made up of a meshwork of caverns and
channels, it is called a _cavernous lymphangioma_; when it is composed
of one or more cysts, it is called a _cystic lymphan