THE INTERMEDIARY HOST OF FILARIA CYPSEEI 
43 
and without sheaths, are seen in the stomach contents. The peculiar tubercle at the 
posterior end is plainly seen, and by it the small embryo can at once be recognized. 
The young filaria now show active progressive movements ; it is probable that, soon 
after casting its sheath, the embryo pierces the stomach wall and, finding its way to 
the fat body, there embeds itself. Length, 84-76 /u ; width, 6-5 to 7-5 1*. Length ot 
tail tubercle, 3* 2 6. 
Stage II (Fig. 3). — Found in the fat body. When dissected out from the fat 
body the parasite generally shows little or no movement. The chief feature of this 
stage is the marked shortening and thickening of the embryo. The tubercle at the 
posterior end is still present, but appears rather smaller in comparison to the increased 
width of the parasite. The slight ridge separating the bodv from the papilla at the 
anterior end of the body is not visible, and the extreme end is slightly flattened. 
The body itself is seen to consist of a central, very granular portion, surrounded by 
a thin hyaline envelope. In some parasites a minute, lateral tubercle may be seen 
situated at the side of the body, at the junction of the anterior and middle thirds, 
also another slight elevation of the cuticle may be seen near the posterior end. 
The following are some measurements of embryos in this stage of their meta- 
morphosis, seen in fresh preparations (normal saline) : — 
Total length 
Central width 
Length of tail cuticle 
81-50 JUL 
9-78 [X 
3-26 fi 
58-68 
16-30 
yz6 
75-24 
18-56 
326 
9+ -8o 
19-50 
326 
Fig. 4 represents the embryo with a much flattened anterior extremity, and 
with evidences of a mouth opening and lips — this appearance has only been seen in 
one specimen, but it is very probable that during the end of this stage development 
of a mouth opening takes place as described by Manson 1 in the metamorphosis of 
F. bancrofti. The embryo, measuring 94-8 /x, is represented in Fig. 5. It shows a 
slight transition from this to the next stage to be described ; the body is differentiated 
into outer and inner layers ; the portion of the anus is clearly distinguished, and 
commencing striation of the body can be seen. 
Stage III. — Stage of elongation and differentiation of the body protoplasm 
(Fig. 6). In this stage of its metamorphosis the young filaria is found greatly 
increased in length, which now progresses much more rapidly than the still increasing 
Manson. Transactions of the Linnean Society, 1884, p. 567. 
