542 Pathological Significance of Nematode Hcematozoa. [part hi. 



fact that they may also be found in the walls of the oesophagus. Notwithstanding 

 the somewhat extended reference to the works of systematic writers on these and 

 allied subjects, which, through the courtesy of Mr. Wood-Mason, Curator of the 

 Indian Museum, I have been able to make, I can find no mention of their lodging 

 themselves in the walls of the blood vessels. 



(2) — As far as the aorta is concerned, the condition referred to under the 

 second heading is the one of most frequent occurrence ; and as in this condition 

 the parasite may be obtained in various stages of advancement, it will be better to 

 describe the smaller tumours and their contents before referring more minutely to 

 the mature Filaria, especially as this will give an opportunity of studying the 

 growth of the parasite from a very early period till it reaches maturity. Specimens 

 in almost every stage of development may sometimes be found lodged in the walls 

 / of a single aorta. 



Although the tumours enveloping the young are much smaller than those in 

 which the mature worms are usually lodged, the lesions, as far as the tissues of the 

 walls of the artery are concerned, appear to be of a more serious nature for 

 frequently the walls of the vessel are very fragile at various places and there is a 

 considerable roughening of its inner wall. 



Towards the earlier stages of the attack of this parasite, a cursory examination 

 of either the inner or the outer surface of the aorta may not convey to the observer 

 the impression that there is anything unusual present, but on closer inspection slight 

 indications of roughening or of dryness of the inner surface will be evident, as if 

 indicative of commencing atheromatous changes. There may be either a small de- 

 pression at the part or a slight elevation, and when the artery is drawn between 

 the finger and thumb, a little tubercle, varying in size from that of a millet-seed 

 to that of a pea, may be more or less clearly evident. (Plate XXXIX, Fig. 10.) 

 Frequently also, on careful examination, a thin serpentine line may be detected lying 

 immediately beneath the inner coat of the artery. (Plate XXXIX, Fig. 9.) 



When one of the smaller tubercles is cut into and the tissues carefully dissected 

 under a low magnifying power, a curled, hair-like object will generally be observed 

 (Plate XXXIX, Figs. 9, 10) ; this, when examined under a higher power, will be found to 



little plate terminating in two or three sharp spikes (Fig. 35. 6), the points being directed backwards. The 

 tail of the male is slightly pointed, has a well-marked transverse slit on its ventral aspect, through which 

 two spicules of unequal length occasionally emerge, and on either side four granular processes (papillte?) 

 are seen to diverge from the middle line, with one papilla-like ray extending to the tip of the tail (Fig. 

 35 4). There is no bursa, properly so called, nor are there distinct alas, but in a state of contraction the 

 orifice through which the spicules escape, is pulled up, so as to give rise to a funnel-shaped cavity. 

 There are numerous transverse rows of minute booklets with the points directed forwards, extending 

 from the caudal orifice upwards, about as far as the upper end of the longer spicule when retracted ; 

 their number and size diminishing as they extend upwards (Fig. 35, 7), 



I have not been able to make out the existence of either oral or anal apertures, nor been able to 

 isolate any structure analogous to an alimentary canal, and conclude, therefore, that the parasite is an 

 Echinorhynchus — possibly a hitherto undescribed species. All the specimens which I have examined have 

 been males. . 



