Page:Transactions of the Royal Society of Tropical Medicine and Hygiene, volume 1.djvu/187

Rh tectorate, where the invasion is great (much greater than in Barbadoes), a number of cases are to be found on searching, but they are not obtrusive, and are clearly not so common as they are in Barbadoes. Of course, in a scattered population such as is found in the Protectorate, it is very difficult to get an idea as to the exact percentage, but a medical officer of great experience put it down as about 5 per 10,000 as an outside estimate.

It is evident that, with varying degrees of infection of the general population with F. nocturna, we ought to have a fairly fixed ratio of elephantiasis, but up to the present we have no proof of this. The only thing we have to go on are impressions that the disease is common. I have taken the trouble to go through the Colonial Office reports, with a view to see what ratio the admissions for elephantiasis bear to total admissions, but unfortunately the reports are absolutely useless for this purpose, as diseases are lumped together under each separate system— "Diseases of Lymphatic System," etc.

We can find many statements like this : Dr. Finucane, speaking of Fiji, says that "it is almost impossible to find an adult person free from elephantiasis in certain districts," "Every growing Fijian child shows signs of 'waganga,' that is, a form of lymphangitis," " Most Fijians are liable to four or five attacks annually," and so on. Now, no doubt these are valuable as records of clinical experience, but we should certainly expect to find some definite relationship between the varying distribution of filariasis and elephantiasis. That up to the present, I submit, has not been shown, and until it is, this particular argument cannot have the force which it would otherwise have.

Now, in considering the question of the relationship between animal parasites and disease, we should, I think, be able to apply similar rules to those which obtain in the case of diseases caused by vegetable micro-organisms:—