556 Pathological Significance of Nematode H^matozoa. [part hi. 



histories of a considerable number of individuals afifected in this manner have been 

 published by me, and that in all the Filaria sanguinis hominis have been detected. 

 I have now traced the Filaria to the blood direct in eleven, and detected them in one 

 or other of the various tissues and secretions of the body in more than thirty individuals. 

 The history of one of these persons could not be ascertained, but all the others were 

 known to suffer, or to have suffered, from Chyluria, Elephantiasis, or some such closely 

 allied pathological condition, 



(2) — With reference to the second clause our knowledge is not so exact, and 

 almost all the inferences have to be drawn from observations made in connection with 

 the Hsematozoon described in previous pages as occurring in pariah dogs. Judging 

 from what may be seen in these, and from data which the only post-mortern examinations 

 which I know to have been made of individuals affected with this parasite, I think 

 that the interference with the flow of fluid in the lymphatic capillaries and smaller 

 blood-vessels may not unreasonably be attributed to one or other of the following 

 causes : — 



a. To tumours, produced by encysted mature entozoa along the course of the 



blood-vessels and lymphatics, impeding the flow of fluid in them by pressure 

 either directly or indirectly by interfering with the functions of the nerves 

 supplied to the part ; 



b. To the active migration of the immature, or rather partially matured parasite ; 



the act of perforating the tissues— nervous or vascular — producing more 

 or less permanent lesions ; 



c. To the activity of the liberated embryos in the capillaries causing the rupture 



of the delicate walls of these channels in which possibly ova may have 



accumulated owing to their size, or an aggregation of active embryos taken 



place, either accidentally, or by the parent having migrated to the capillary 



termination of a blood-vessel and there given birth to a brood of microscopic 



blood-worms. Once the walls of the capillaries have given way the embryos 



pass into the adjacent lymph channels, the boundaries of which are so 



• extremely delicate as practically to offer no impediment to the further 



progress of such active organisms. Should the lymphatic spaces be situated 



in intimate relation with a secreting surface, the escape of the minute Filarice 



as well as the escape of fluid from the lymphatics with the ordinary secretion 



of the part, would seem to be a natural consequence. 



At present I do not see that the facts at my disposal warrant any further deductions, 



but I trust that the description of the observations which have been made have been 



sufficiently clear that readers will be able to judge for themselves how prominent a 



part such a Hsematozoon may play in the causation of some of the diseases peculiar to 



tropical climates. 



Calcutta, 



1874. 



