.
COLOUR AND PHOSPHORESCENCE
189
about an hour and then disappeared.”
In our own seas
the
vividly phosphorescent jellysh is the rounded
'
'
Pelagia noctiluca (Plate 73) whiCh is however much more
abundant in the Mediterranean. '
The method
of light
-
production is probably similar to that of Noctiluca only
on a much larger scale, there are no special light Organs
but a stimulus of any kind, such as that caused by the
passage of another animal, causes the whole animal to glow
with light.
Another animal related to the jellyshes and
even
more
intense—ly phosphorescent is the Sea Pen, Peñ—
%dtula phosj>howäa (Plate 73), which lives in _mùd off the west -
.
'
of Scotland and Scandinavia.
When brought to the surface '
the slightest touch at any part will cause that region to.
light up=--in the darkness, the light then spreading from
_
branch to branch until the whole is aglow.
The large
Sea Pen, Funiculina quadrangulam‘s which may be siX
,
feet long, is, according to Professor
especially
phosphorescent along the main
which, if gently
'
touched, glows with light which travelsùp and down like
,
a ickering ame.
'
'
,
The most phosphorescent of the worms is, pecu_liarly
enough,- one called Chætopterus Which spends its
life hidden in a parchment—like tube
in mud with
only the head end protrudin‘g (Fig.animal
produces a luminous substance-mixed with
almost the entire Surface 'of the body. The light in this
in usually violet or bluish‘ green, and a similar colour
is given by many.ôther small marine worms. In some ot
'
these, Such as.onecalle”d.Odontosyîiis fromBermuda, the,
production of light .isa..Canerned'Ï—ziwäth. reproduction, light
being produced only during the: reproductive season when
,
the animals 'sWarm in the sea for—. mating, and never at other
times.
.'
'
When we come to the crustace&nsrwe nd
more
COLOUR AND PHOSPHORESCENCE
189
about an hour and then disappeared.”
In our own seas
the
vividly phosphorescent jellysh is the rounded
'
'
Pelagia noctiluca (Plate 73) whiCh is however much more
abundant in the Mediterranean. '
The method
of light
-
production is probably similar to that of Noctiluca only
on a much larger scale, there are no special light Organs
but a stimulus of any kind, such as that caused by the
passage of another animal, causes the whole animal to glow
with light.
Another animal related to the jellyshes and
even
more
intense—ly phosphorescent is the Sea Pen, Peñ—
%dtula phosj>howäa (Plate 73), which lives in _mùd off the west -
.
'
of Scotland and Scandinavia.
When brought to the surface '
the slightest touch at any part will cause that region to.
light up=--in the darkness, the light then spreading from
_
branch to branch until the whole is aglow.
The large
Sea Pen, Funiculina quadrangulam‘s which may be siX
,
feet long, is, according to Professor
especially
phosphorescent along the main
which, if gently
'
touched, glows with light which travelsùp and down like
,
a ickering ame.
'
'
,
The most phosphorescent of the worms is, pecu_liarly
enough,- one called Chætopterus Which spends its
life hidden in a parchment—like tube
in mud with
only the head end protrudin‘g (Fig.animal
produces a luminous substance-mixed with
almost the entire Surface 'of the body. The light in this
in usually violet or bluish‘ green, and a similar colour
is given by many.ôther small marine worms. In some ot
'
these, Such as.onecalle”d.Odontosyîiis fromBermuda, the,
production of light .isa..Canerned'Ï—ziwäth. reproduction, light
being produced only during the: reproductive season when
,
the animals 'sWarm in the sea for—. mating, and never at other
times.
.'
'
When we come to the crustace&nsrwe nd
more