ECONOMY OF THE
,
143
'
communication of the 'pericardial cavity With the abdominal
cavity, and thence With the exterior,' may” contribute to
.
'
the difference. ; The tissues are more "permeated .by' the
,
'
medium.
7
,
'
l
,
.-…,g
_:5:
=
.
'
How far the tissues
young :iàWat and
'
stages can be_ permæted directly
and soluble
salts, is an interesting question. We may-certainlÿjfläfelieveŸ’
.
thàtwater can pènetraté through
spidernë;ädf it
'
is prObable
'
'
'
Closer contactWith the
these-to SWell
,
'
as in the case of the
;" and it5i‘s alsofiprobable
'
that—the
ScalyÇœvering'depends just'up‘on ' '
the ‘dilutionof the=colloidSubstances in the defns by the "
:
water”.
.
ButWeÏ know extremely
yet regarding these
interesting andimportant phenomena. If Pütter is cOrreCt
_in his
that dissolVed substances can be‘taken in through
"
just as poisons"can‘ enter in the same Way,
>
it becomes: —,a doubtfùl matter 1f the’yôung 'Sh“i —is so
.
“independentÿof‘the—externalmedium. ; -‘L
"
, ' —' _
Wh115t1t18clearthatthehvmgmembranesareœgulatmg
forcesmtherelatmnïéftheshto
,
'
âglandswh1chhaveæpecuharpropertyof bemgableto : :
'
f ‘
sec1etevanousorgamc substances thatpass 1ntothe blood
; ', ,
'
or‘
n0t into the
thuscon—
veyed through the system to all— parts”
'
_
;
These substances have been called “
the sti1‘1‘ers '
u'p, since they are specic in their action, aecting special
organs and thus stimulating or retarding the activities and
growth
distant
.
places.
The
“
vital humeurs ” of the
.
perhaps the most tting expression for them in
popularlanguage..
"
'
_' -' The peCulia'ritÿ-of acting atadistance is,
,
f
_
restricted to these ':Substances.
It
long beenknown,
j
;'
:for eXample, that the car‘bonic acid formedmmuscleaects
;
if the Jbreathing centre ,in the :medulla' a_ndlthàtÿaalbùréï:
f
Î] : theÿblOod, affects the: liver," Wl_1ilst<1epancreasrequ1resthe
-
'
'