FILAELSL 65 



lymphatic distension below the obstruction. When the thoracic 

 duct itself is the site of this obstruction its tributaries become 

 varicose, and a collateral lymph circulation is attempted; the 

 chyle stream becomes actually reversed in the lower part of the 

 duct and passes by way of the pelvic lymphatic trunks to the 

 femoral and inguinal regions and scrotum, and thence upwards 

 in the abdominal walls to reach the lymphatic system of the upper 

 part of the body. The varicose lymphatics of the collateral 

 circulation tend to give way and discharge the chyle they convey 

 under these altered circumstances. They may weep on the 

 surface of the skin, fill up the tunica vaginalis testis with 

 chylous fluid or rupture on the surface of some part of the 

 urinary mucous membrane and give rise to chyluria. The 

 inguinal and femoral groups of lymphatic glands which are 

 interposed in the course of the reflux stream become swollen 

 from varicosity of their lymph spaces, and the lymphatic tissues 

 of the scrotum are swollen by a similar mechanism. The enlarged 

 lymphatics are in situations exposed to slight injury, and may 

 become acutely inflamed. 



In some cases the lymphatics are thought to be blocked in 

 another way, i.e., by the discharge of immature ova from the 

 filaria nocturna, practically an abortion, for the worm is normally 

 viviparous. The ova, on account of their breadth, are not 

 capable of traversing the lymphatic trunks, and consequently 

 become impacted in the efferent lymphatics of the part of the 

 body in which the worm is ensconced. Elephantiasis results in 

 the part thus deprived of free lymphatic drainage. Under such 

 circumstances it is easy to see that filarial embryos may be 

 absent from the general circulation and yet found in the lymph 

 of the diseased member. The presence of filarise in other parts 

 of the body will probably explain those instances where the 

 embryos are found in both situations. 



C.A.A. 



