FISHES
THE WEB OF LIFE
291
remains of a drab appearance, but in Some cases, for example,
the freshwter SticklebackS, the female also assumes '
a
bridal dress.
As a rule the female is larger than the male.
Formerly, it was thought that these, differences in the
,
sexes had been developed by some process
the
females chobsing the
partners WhilSt
drab colour‘s were, a protection to them. As a better
of the phenomena, hoWevéi‘, it is now more
generally believed that the colours and—l'ether. characters
are
simply…attri‘butes of
“ maleness'.”
-The- hormones of
the sexual organs, are convey_ed by the blood and lymph to
the different piäfts,.peetoral orventral ns of m0uth, which
the-different grOups
as
special organS in -, ,
Connecti0n With the pairig. That the males usually have 'a ;
more brilliant colOration than the females is due to their
greater metabolism and activity.
_, :__
f-,——__z.
The males of some forms have structures
the females which seem to have nothing to do with the act ‘
-
of reproduction.— In some species of_ thé. at—È'sh Arno—
=glossus the anterior rays of thedorsal n are more elongated
in the male than the female, whilst in the allied;genus Bothus
the.
eye of the male travels further back on the
head than in the female, whilst at the same time parts of the
month , boues project as tubercles thr0ugh the skin. In
these cases the differences can be asctibed to a difference
in the balance of the whole body between’ the males and
.
femalés. The old males of the Salmon also develop a
peculiar mouth. The maxillaries above separate, forming
a groove in the middle into which ts a very peculiar growth
of the lower jaw.
lt uSed to be thought that this peculiar
hook was a kind of ,spade used in working holes to receive ,,
Bur, so”far‘
known, the female is more
_
Without ñ—the,
operati_on._ Other
—
have
_.
female Or,
protectiveorganofsomesort,
' _
these explan‘ations donottthe facts
,
“The leastVlolnt
explanabon ppt
.
bbbhbt bbbfiboobÿ is…,annty
pathological
_