OF THE
149
activity. As noted in the previous chapter, they are also
remarkable for the large amount of urates in, the blood,
which_may also be taken asa sign of enhanced metabolism.
On the other hand, the pink-colour of the Salmon muscle —
is due to the presence
special-pigment, lipochrome,
deriVed apparently from
Copepoda;on
feed_(Newbigin, 1900).
r -
__
=:
By taking a series of nCrophot0graphs Hürthlé‘has been
able to follow the physical changes occurring inthe muscles
of living insects. The brillæ or striated threads of a muscle
cell are embedded in a clearlayer of liquid (sarcoplaSm) and
the same clear layer is present at the ends of a row of the
\
striatedcells.
Whenthe,elastie brillæ contract, the liquid
_
of the sarc'oplasm is. forcedout into the end layers. The
brillar portion may contract to ”half of its previous length or
even more, buf';itS.total
constant. '
'
=
Onefof…the most remarkable phenomena in nature is the
,
_
.
Way ;ih Which certain "shes have converted the, ordinary,
'
living muscle Cells {into powerful electric
It
'
illustrates hOW
the
forms- 'Of energyîare‘ con—'
.
,
cannot but marVel
the
by the
shesof agpower
inhigher animals,:even in
'
man _,Their conversion ofpbtential‘into kinetic energy in the
muscles With little orno Waste of heat
notedÏab0ve ;
_
—
here it is converted directly into- “a form
_
tension.
The shes rpossessin'g these organs
mostly of
'
a sluggish nature and it would seem as’if the potential energy
.
stored up in the muscle cells, and not used in active work,
had caused a reduction of the elastic, internal brillæ and
—
concentrated on the outer and opposite margins, which
thereby have become like positive and negative poles towards
one another (Fig. 35).
-
_
»
-_
‘
_
._
The close connection between the
'
._
the muscle cells was already eVident to _Robin‘aslongl àlgÔ.S
‘
1847, but it isto Bahukhin (1870) that we OWe_
proo The ordinary Rays—; have tWoi Small Organe
th1s
"
kind near the end 0f;—the tail, ;whichzg‘rade into ‘;the-stri‘ated
“_
muscle bres in:front, .ï; T
,
.