SOME PARASITES FOUND ON FISHES IN THE 
IRISH SEA. 
By AnpREw Scorr. 
No subject offers a more enticing attraction to the 
Zoological student than the one that deals with those 
members of the animal kingdom which through some 
acquired habit have become partly or altogether dependent 
on other animals for their food. This branch of research 
has been very prominently brought to the front within 
the last two years by the further investigations relating 
to the formation of pearls in the common mussel of our 
sea shores, by Dr. IH. L. Jamieson, and of the extremely 
valuable oriental pearl from the Ceylon pearl oyster, by 
Professor Herdman and Mr. James Hornell. 
It has long been known that the completion of the 
life cycle in some parasites, such as the “ liver fluke ” in 
sheep, is wholly dependent on part of the development 
being carried on in another animal; and it is becoming 
more and more evident that the life-cycle of these parasites 
can only be completed when the creature has successfully 
passed from one stage to another, and reached its final 
host where reproduction takes place. 
The difficulties that await the student who contem- 
plates investigating the life histories of parasites are great, 
but by no means insurmountable. Extreme care and 
much patience are necessary, but the work is well worth 
the labour expended and there is still much to do. 
In the following notes a list of the parasites that have 
been recorded from the fishes caught in the Irish Sea is 
given, with remarks on some of the more important points 
connected with each. It is probably far from exhaustive, 
but will form a foundation for future additions. Up to 
c 
