HYPOTHESES 93 



The onset of elephantiasis varies. In some cases it 

 may be gradual, without pain, fever, or any local inflam- 

 mation. The patient notices that the limb begins to 

 swell and that this swelling continues. In many of these 

 cases after a time attacks of lymphangitis occur. More 

 commonly there is a sudden onset, with fever, often 

 rigors, and the limb becomes swollen, painful and hot, 

 and is red and obviously inflamed. Such an attack 

 resembles erysipelas, and is known in the West Indies by 

 the old English name for that disease, " rose." It is not 

 often fatal, but abscesses may occur, and red lines in the 

 course of the lymphatics above the swollen part may be 

 seen, and the glands, whether previously enlarged or not, 

 become swollen and tender. The acute symptoms pass 

 off, and the swelling subsides to some extent but not 

 completely, and after a time the- painless chronic oedema 

 supervenes and steadily increases. 



Frequently there is a series of such erysipelatoid 

 attacks at intervals of weeks or months, and each attack 

 leaves the limb larger than it was before, and even in the 

 intervals increase in size takes place. These erysipelatoid 

 attacks usually commence without any warning or any 

 local skin lesion or injury ; but they are more frequent 

 in the wet weather and after heavy rains. Most of the 

 persons attacked go about bare-footed, so that they are 

 exposed more to the risk of injuries which may escape 

 notice. Thrombosis of the veins occasionally occurs. 



Any hypothesis which can be regarded as affording 

 a satisfactory explanation of the causation of elephan- 

 tiasis must explain : (i) The distribution of the oedema, 

 which does not always correspond with a blockage of 

 main lymphatic vessels ; (2) a gradual onset without 

 acute inflammatory symptoms ; (3) the onset with an 

 acute inflammatory attack or recurrent inflammatory 

 attacks ; (4) the absence of filarial embryos from the 

 blood and usually from the lymph of the affected part. 



The known ways in which lymphatic obstruction is 

 produced by nlariae, namely, by causing haemorrhage or 



