PART III.] Minute Description of " Filaria Sanguinis Hominisr 5,13 



mistaken for anything else. The remark made by a young Bengalee student on my 

 requesting him to look into the microscope and tell me what he saw — " He is an incom- 

 pletely developed snake, evidently very young, though very active " — so aptly describes 

 the object as thus witnessed, that I feel sure that any one seeing the Hgematozoon alive 

 will not fail to be struck with the accuracy of the quaint reply. 



During the first few hours after removal from the body, the Filaria is in constant 

 motion, coiling and uncoiling itself unceasingly, lashing the blood corpuscles about in 

 all directions, and insinuating itself between them. It is not at rest for a single 

 moment, and yet on one slide it appears to make but little progress, and it may 

 frequently be watched for an hour in the same field without once giving occasion to 

 shift the stage of the microscope. No sooner has it insinuated its " head " amongst 

 a group of corpuscles than it is retracted, and probably the next instant the " tail " 

 will be darted forth and retracted in a similar way. 



One moment it may appear to possess a long "tail" — a fourth or more of its 

 entire length, which follows it through the fluid like a string, whereas the very next 

 moment not a trace of the " tail " can be seen even with the highest powers. The 

 same phenomena can be observed to take place at the thicker, cephalic end, but with 

 more difficulty. As usually seen, this presents a blunt or slightly tapering termination, 

 but every now and then a fine point like a fang appears as if darted straight forward 

 out of its substance ; the next instant the creature may jerk its " head " on 

 one side and the "fang" becomes bent and drawn after it like a ribbon (Fig 31, 

 page 509). 



As seen with a \'' objective, these Haematozoa can scarcely be said to present a 

 granular aspect. When only recently withdrawn from the body, they look smooth 

 and almost translucent ; the larger specimens, however, frequently present an aggregation 

 of granules towards the junction of the middle with the lower half, as may be seen 

 represented in a few of the specimens delineated (Fig. 31). Occasionally also a bright 

 clear spot is observed at the thicker extremity extremely suggestive of an oral aperture ; 

 this likewise is represented in some of the figures in the woodcuts. 



They will continue thus active under a covering glass, hermetically sealed, for 

 from 6 to 24 or 30 hours ; and if a drop of blood be suspended from the centre of a covering 

 glass and fixed to a ring of wax, thus forming a closed cell, the Hgematozoa may live 

 for three days, perhaps longer, but this is the longest period during which I have 

 known them to retain their activity. 



It must not be inferred that the group of Haematozoa depicted in this woodcut 

 (Fig. 31) represents one field of the microscope, but only that the particular specimens 

 were observed on a single slide. The same remark applies to the second group depicted ; 

 except, that two of the figures in it represent Filarise found in other preparations 

 obtained from the same individual. 



35 



