162
A. D. BONEY
enhanced growth in increased illumination could be fragmented, and
the separate fragments still be fertile. The young sporophytes then
obtained were cultured under variable conditions of salinity and
temperature. I n water of salinities 25 and 30"/,,, satisfactory growth
was obtained at temperatures up to 14"C, but poorer development waa
observed a t lower salinities (16 and 20"/,,). At higher temperatures
(17OC) the plants kept in media of low salinity died, and those at 26
and 30°/,, were in a poor condition. All the young sporophytes were
killed at 20°C.
Sundene considered that summer temperature was the principal
factor governing distribution of Alaria. In fact, distribution was found
to be almost limited to coasts where the mean surface temperatures
remained at 16°C or below.
12. Nereocystis luetkeana
This species is another of the giant kelps found on the western
coast of North America, frequently growing mixed with Macrocyatia,
(aa on the coast of British Columbia (Scagel, 1961) ). The plant consists
of a long flexible stipe which terminates in a vesicle, and this vesicle
bears numerous lanceolate blades. The plant grows in 6-8 fathoms of
water, usually where tidal action is swift (Fritsch, 1946). Growth of the
plant is annual, so that only one harvest per year is possible. I n this
case, however, it would be important to delay harvesting until fruiting
had been sufficient to allow some recuperation of the standing crop
(Scagel, 1961). The sporangia are borne in elongated sori on fertile
blades, and the entire sorus degenerates and falls out when fruiting is
completed. There appears to be little information on the gametophytic
phases in the life history. The heavy loss of frond tissue after fruiting
indicates that this is a serious feature to be considered with regard to
harvesting. A number of alternative uses other than &B a source of
dgin have been suggested for Nereocyatis (Chapman, 1960; Scagel,
1961 ; Newton, 1960, 1963).
13. Egregia
This genus, which is related to Alaria, grows in extensive stands in
the region of the sublittoral fringe and just below on the western coasts
of North America. The plant consists of somewhat flattened stipes and
fronds which are fringed by numerous short laterals, many of which h v e
an assimilatory function. Plants can reach lengths of 30 to 40 ft, and
could be a potential source of harvestable weed. However, few attempts
appear to have been made to exploit this plant on a commercial basis.
A. D. BONEY
enhanced growth in increased illumination could be fragmented, and
the separate fragments still be fertile. The young sporophytes then
obtained were cultured under variable conditions of salinity and
temperature. I n water of salinities 25 and 30"/,,, satisfactory growth
was obtained at temperatures up to 14"C, but poorer development waa
observed a t lower salinities (16 and 20"/,,). At higher temperatures
(17OC) the plants kept in media of low salinity died, and those at 26
and 30°/,, were in a poor condition. All the young sporophytes were
killed at 20°C.
Sundene considered that summer temperature was the principal
factor governing distribution of Alaria. In fact, distribution was found
to be almost limited to coasts where the mean surface temperatures
remained at 16°C or below.
12. Nereocystis luetkeana
This species is another of the giant kelps found on the western
coast of North America, frequently growing mixed with Macrocyatia,
(aa on the coast of British Columbia (Scagel, 1961) ). The plant consists
of a long flexible stipe which terminates in a vesicle, and this vesicle
bears numerous lanceolate blades. The plant grows in 6-8 fathoms of
water, usually where tidal action is swift (Fritsch, 1946). Growth of the
plant is annual, so that only one harvest per year is possible. I n this
case, however, it would be important to delay harvesting until fruiting
had been sufficient to allow some recuperation of the standing crop
(Scagel, 1961). The sporangia are borne in elongated sori on fertile
blades, and the entire sorus degenerates and falls out when fruiting is
completed. There appears to be little information on the gametophytic
phases in the life history. The heavy loss of frond tissue after fruiting
indicates that this is a serious feature to be considered with regard to
harvesting. A number of alternative uses other than &B a source of
dgin have been suggested for Nereocyatis (Chapman, 1960; Scagel,
1961 ; Newton, 1960, 1963).
13. Egregia
This genus, which is related to Alaria, grows in extensive stands in
the region of the sublittoral fringe and just below on the western coasts
of North America. The plant consists of somewhat flattened stipes and
fronds which are fringed by numerous short laterals, many of which h v e
an assimilatory function. Plants can reach lengths of 30 to 40 ft, and
could be a potential source of harvestable weed. However, few attempts
appear to have been made to exploit this plant on a commercial basis.