270 Transactions.— Zoology. 
Positive proof of the species infesting the skin can only be ascertained 
by those having opportunities of searching for them at the proper time, 
when this pseudo-scab is prevalent. 
The lung-worm in sheep. 
The result of an examination of a portion of a sheep’s Tuas forwarded 
by the Stock Department is as follows:—The sheep was depastured at 
Marton and was killed in June last. Near the opening of the bronchial 
tube was found a contorted heap of filiform white worms, which, on exami- 
nation, proved to be a species of Strongylus. All the specimens examined of 
this travelling detachment, were found to be packed with eggs, each egg 
showing under the microscope a coiled embryo within, in an advanced stage 
of development; a large portion of the lung structure was found to be per- 
fectly healthy, and evidently had not been visited by the worm, but in the 
remaining portion some worms were found which proved under the micro- 
scope to be nearly filled with eggs, none of which, however, showed any 
traces of an embryo, thus no doubt explaining their delay in moving with 
the others ; male worms were also found here. This portion of the lung 
proved to be in a diseased state, being flabby and white, the worms having 
evidently burrowed through its body and formed a lodgment there till they 
should arrive at their normal size and become fertile with ova. It appears 
that they remain in the lung till the embryos reach the mature stage of 
bursting their envelopes, when the parent worms commence to evacuate 
their temporary abode and move towards the damp ground, where they find 
the conditions best adapted for the first stage of life of the young worms, 
and where the parents no doubt die. 
It is at this travelling stage that the worms become most dangerous to 
their host, in proportion to their numbers, filling the air passages of the 
lungs and nostrils, and often when numerous in weak sheep or lambs 
causing suffocation. The life-history of this nematode clearly shows that 
it only occupies the lungs of sheep for a few weeks during summer ; leaving 
the ground in spring while yet in an immature condition and scarcely 
visible to the unassisted eye, and crawling up the nostrils of the sheep, they 
reach the lungs without causing much annoyance. The period of escape 
by the same track in autumn, after they have reached their mature ¢on- 
dition and become fertile with embryotie ova, may extend over several days, 
during which time the sheep labour under great annoyance, and if the 
worms are numerous are in much danger of suffocation; as they advance 
towards the nostrils in contorted balls and fill up the air passages, 
a a From what has been said i 
* Hane 
—— of the embryo occurs in some worms we 
ty . : : Pay ee ee ninishing the C : 
