STRONGYLUS ARMATUS. 
worm inside each tumor. The latter also contains altered 
blood or pus, and there is more or less hyperasmia around 
die circumference. The worm within is rolled upon itself, 
md is, of course, of variable dimensions, sometimes extremely 
ins, and never so large as in the adult state; it is always des- 
;itute of reproductive organs. 
Occasionally there is no worm in the tumor, and then there 
s seen a small opening at the summit, by which it has escaped. 
The worms found in the organs,-mentioned above are also 
igamous ; they represent the primary phase of development, 
is they do not become sexualized except in the caecum and 
:olon. 
Colin states that the armed sclerostomes are worms which 
nigrate internally, and that their development is effected 
ilmost in one place. The ova are deposited in the substance 
if the intestinal mucous membrane—perhaps in the punctures 
iroduced by the mouth of the female, or perhaps merely in 
he orifices of the glands—and they are hatched there, the 
anbryos becoming encysted at the points where they are 
latched, in the cyst developed by their presence. 
After being developed and having undergone several 
noultings, they make their exit from the cyst, and fix them- 
elves on the surface of the mucous membrane ; though a 
:ertain number remain in their cyst, grow there, have the 
genital organs partly formed, but nevetheless always remain 
gamous. Those found in aneurisms and in the peri-intestinal 
>rgans, must have entered the blood vessels on their leaving 
he cyst, and in this way be carried—by a centrifugal migra- 
ion—to the parts where they are found. 
Railliet has shown that this is not the ordinary mode of 
eproduction and development of the sclerostomes. The ova 
re expelled along with the fasces, and become hatched in a 
ew days if they are in a damp place. The embryos that 
ssue from them are cylindroid, a third or a fourth of a milli- 
netre long, somewhat obtuse in front, and have a filiform tail, 
f the conditions of humidity continue to be favorable, they 
gradually grow, their integument becomes folded and forms 
kind of sheath in which the worm moults in an evident 
