FILARIA MEDINENS1S. 321 
The silence of Pison and other writers as to the worm 
being the cause of disease among the natives, proves no 
more the immunity of these than does the silence of Dazille 
or of Sing Gomez Ferreira prove that of the blacks of whose 
diseases they wrote during the time of the slave trade; for 
it is incredible that neither of these observers had ever heard 
of the Filaria Medinensis, even if we could suppose they had 
never met with a single case of their own among the blacks 
they had to treat. 
The existence, therefore, of the Dracunculus endemically 
in this country before the importation of Africans, cannot, I 
think, for want of authentic documents as to this part of our 
medical history, be positively either affirmed or decided; at 
most it may be conceded that the second alternative, which 
would look upon the importation of Africans as the sole 
cause of its introduction among us, is the more probable of 
the two. But granted the truth of this hypothesis, we have 
still to look for an explanation, if not of the fact of its now 
or recently existing endemically in the neighbourhood of the 
Feira de Santa Anna, at all events of why it should exist 
only in localities so thinly peopled, at a distance not only 
from the coast, but from this capital, where recently-arrived 
slaves from Africa were wont to be crowded by the thousands. 
By what strange caprice of fate did it come about that the 
accursed seed was blown to such a distance, leaving intact 
our own vast lake, and all the suburban rivulets and dams 
as well as the reservoirs of so many sugar plantations, all 
along our bay, where new blacks were received in troops, 
many of them already infected with the Dracunculus ? It is 
surely only reasonable to suppose that the parasite, if im¬ 
ported, should exist more abundantly in those localities 
where its importers, or “ living vehicles,” as my talented 
colleague the author of the remarkable thesis that suggested 
these reflections well designates them, were themselves 
most numerous. 
On the other hand, we see almost at the same time 
Wucherer in Brazil, and Lewis in India, have brought under 
the notice of the scientific world another parasitic nematoid, 
also an endemic filaria whose coexistence in two so widely 
separated countries, having no direct communication with 
one another, cannot, with any plausibility, be attributed to 
their transport by <e living vehicles.” 
However it be, the problem of the primitive origin of the 
filaria among us must remain for long, if not for ever, 
insoluble. Some light, however, may be thrown on the 
subject by the co-operation of other colleagues, having the 
