ArTHUR.—On the Brown Trout introduced into Otago. 507 
Neither as yet have I discovered any cases of two or any bones of the verte- 
bre coalescing or subdividing. Whether young trout have fewer vertebre 
than older ones, has not been examined into by me, but I suspect it may 
be so. 
The Pyloric ceca situated at the end of the stomach where it forms a 
second bend in joining the great intestine or gut, appear to possess the 
functions of assisting in absorbing and assimilating the food from the 
stomach, and of secreting fat. In external colour they possess a rosy flesh 
tint, when the trout is in good health and on its natural food, and in form 
are exactly like miniature sausages. But I recently examined the intestines 
of a trout taken from a pond, where the trout had been fed largely on 
curdled milk, and where they were fat, strong, and in good condition, when 
I found the ceca perfectly white, while the other organs were more or less 
of the same colour. The interior of the ceca, I have often remarked, con- 
tains an opaque fluid or juice, of an orange, red, or paler hue as the case 
may be, and very much the same as is present in the intestine itself; while 
the exterior is covered by more or less fat, at times indeed smothered in fat, 
which is tied and laced in a most intricate and secure fashion to the 
stomach and ceca by strong fibrous tissues like threads. The fat is whitish 
in colour. From twenty-one female and seven male trout examined, and 
which were taken from nine different rivers, a lake, and from Otago Har- 
bour (two from each of the latter), the number of ceca was found among 
the females to range from 33-61, the mean number being 47:3; while 
among the males the range was from 37-55, with a mean of 48:7. This 
shows that while the range in number is great (but among males not so 
much so as among females, just as with the fins), the mean number does 
not seem to vary much over the whole, or as between the sexes. But un- 
doubtedly as a means of distinction between the fario and its nearly related 
species, a comparison of the above figures with those given in Günther's 
“Catalogue of Fishes,” will prove to anyone curious on the subject that 
they are of no use whatever. I except, of course, the Loch Leven trout 
from this category. 
Ichthyologists say, and with apparent reason, that marine fishes are 
furnished with more ceca than fresh-water forms as a general rule, because 
they have a wider field to range over for their food, and are in so doing 
exposed to more numerous and varied enemies than in fresh waters; and 
that this necessitates the rapid digestion of food, and quick locomotion. 
Applying this rule to such a restricted field as our trout supply—or rather, 
I should say, applying to our trout for such contribution as their limited 
circumstances can afford to our knowledge on this point—I cannot find 
that the theory is supported as yet, our brown trout having nearly as many 
