BOEING LIFE
145
-
Cause ther‘oof is peorated by:ä. regular series of neholes
.
(Fig. 32)- like minute “ man—holes” which—probably help —
the animals within to maintain the necessary circulation
-
of water within the burrow.
The female "appears to do
'
most of the work, for, though there are usually a pairof
Gribbles in each burrow, the female is invariably at the -.
head end.
When the males are touched they will Crawl
backwards slowly out of the burrow,but the fetnales on
.
—
similar provocation will brace themselves rmly against
-
the side of the cavity by means of their broad
and
successfully resist attempts to pull them out.
Probably
'
En france
Respm: for!
FengaJê
Sea.
,
fo burraw
/>IfS
fa/e
_
;
wafer.._
…
-‘
‘
“Ë
**
,——-—___
FIG.
32.——Diagram to show method of burrowing of the Gribble, Limnoria.
Slightly enlarged.
‘
.
they brace themselves in this manner when boring, for
essentially the same purpose as the Shipworm uses his
sucker-like foot.
‘
,
_
Instead of the myriads of minuté eggs which the Shipworm discharges, the female Gribble only produces about
twenty or thirty eggs but she takes very good care of these
and incubates them in a special
“
brood-pouch
”
beneath
her
body.
There the
deVelOping - Gribbles remain till
they have reached a relatively large size and __
when they
nally hatch out-they are about one-fth the size of their
.,
parents and are fully formed animals capable of proceeding
_
immediately about their life’s business of _bormg.
They