202
A. D. BONEY
it was not present until the mannitol reached a certain critical value.
The small quantity in the stipe showed little seasonal variation. The
mannitol content of the frond increased throughout the summer, and
that of the stipe showed a smaller value in the spring when new frondage
was being formed. The protein contents of the frond were highest at
the beginning of the year. The seasonal fluctuations of the reserve
products of L. digitata showed maximal values earlier in the year than
those of L. hyperborea. The alginic acid content of the frond was at
its lowest value in midsummer, whilst that of the stipe fluctuated very
T ~ L E
X. RANGE OB VARIATION (AS yo CO~~POSITION ON A DRY WEIGHT BASIS)
OB THE MAIN E X T R A C ~ S
OF BROWN ALQAE. SHOWN AS MINIMUM AND
M ~ X I M W M QUANTITIES OBTAINED OVER YEAR.
(A = dginic acid; B = m d t o l ; C = lamintwin)
XpeCk
Minimum
Maximum
Authority
-A
B
C
A
B
C
Laminaria aaccharina
L. hyperborea
.
Alariaeaculenta .
L d i g i t u t a .
AacophyUum nodoaum
Fumaaematua .
F.veaiculosus
.
F.8piTdk .
. 13 4.6 0 22.6 22 23 Black,1948a
. 19.6 6 0 27 26 21 Black,1948a
. 14.6 6 0 24.6 18 18 Black,1948a
. 21 4 0 42 12.6 34 Haugand
Jensen,
1964
. 24.6 6.6 2.6 28.6 12-6 7 Black, l948b
. 17 6 2.6 22 16.6 10.6 Black, 1949
. 13.6 9 2 17 16.2 6 Black, 1949
. 14.3 6
1.6 16.6 11-6 8-76 Black, 1949
(All data for whole plants ; differences 'between plants from open sea and sheltered
localities can &o be seen in the references quoted, and the values for fronds
and stipes separetely.)
little. The laminarin content of the frond was negligible between January
and April ; the peak quantities were observed in summer and autumn.
Mannitol in the frond was at its highest value in June, with a second
pe& in early autumn, and fell to a minimum in early winter ; the stipe
content followed a similar variation but between much narrower limits.
The protein content of the frond was higher in the early months of the
year, and low in summer and autumn. The stipe values showed little
variation. With Laminaria saccharins frond variation was the most
significant, and the alginic acid was highest at the beginning of the
year, and at a minimum in the summer. There was little seasonal
A. D. BONEY
it was not present until the mannitol reached a certain critical value.
The small quantity in the stipe showed little seasonal variation. The
mannitol content of the frond increased throughout the summer, and
that of the stipe showed a smaller value in the spring when new frondage
was being formed. The protein contents of the frond were highest at
the beginning of the year. The seasonal fluctuations of the reserve
products of L. digitata showed maximal values earlier in the year than
those of L. hyperborea. The alginic acid content of the frond was at
its lowest value in midsummer, whilst that of the stipe fluctuated very
T ~ L E
X. RANGE OB VARIATION (AS yo CO~~POSITION ON A DRY WEIGHT BASIS)
OB THE MAIN E X T R A C ~ S
OF BROWN ALQAE. SHOWN AS MINIMUM AND
M ~ X I M W M QUANTITIES OBTAINED OVER YEAR.
(A = dginic acid; B = m d t o l ; C = lamintwin)
XpeCk
Minimum
Maximum
Authority
-A
B
C
A
B
C
Laminaria aaccharina
L. hyperborea
.
Alariaeaculenta .
L d i g i t u t a .
AacophyUum nodoaum
Fumaaematua .
F.veaiculosus
.
F.8piTdk .
. 13 4.6 0 22.6 22 23 Black,1948a
. 19.6 6 0 27 26 21 Black,1948a
. 14.6 6 0 24.6 18 18 Black,1948a
. 21 4 0 42 12.6 34 Haugand
Jensen,
1964
. 24.6 6.6 2.6 28.6 12-6 7 Black, l948b
. 17 6 2.6 22 16.6 10.6 Black, 1949
. 13.6 9 2 17 16.2 6 Black, 1949
. 14.3 6
1.6 16.6 11-6 8-76 Black, 1949
(All data for whole plants ; differences 'between plants from open sea and sheltered
localities can &o be seen in the references quoted, and the values for fronds
and stipes separetely.)
little. The laminarin content of the frond was negligible between January
and April ; the peak quantities were observed in summer and autumn.
Mannitol in the frond was at its highest value in June, with a second
pe& in early autumn, and fell to a minimum in early winter ; the stipe
content followed a similar variation but between much narrower limits.
The protein content of the frond was higher in the early months of the
year, and low in summer and autumn. The stipe values showed little
variation. With Laminaria saccharins frond variation was the most
significant, and the alginic acid was highest at the beginning of the
year, and at a minimum in the summer. There was little seasonal