Page:The Botany of the Antarctic Voyage.djvu/536

500 the capsules of a Nitophyllum: whether they be an abnormal development, or organs of fructification rarely developed in the genus, may be a point of dispute. At first sight they were supposed to be caused by the puncture of an aquatic insect or other animal; but their appearing in specimens from different localities; their position, constantly at the angles of the greater areolæ, where four of these meet; their uniform size; the constant presence of the cavity filled with elliptic spores, taken especially along with the fact, that there is no sign of disease or lesion in the frond, would indicate these to be organs in a normal condition.

Plate CXCIV. Fig. II. — 1, Var. α.; 2, var. β.; both of the natural size; 3, apex of frond; 4, portion of ditto with conceptacles; 5, portion of ditto more highly magnified; 6, vertical section of conceptacle; 7, grumous contents from ditto; 8, spores from ditto: — all very highly magnified.

1. ENTEROMORPHA compressa, Grev. ''Alg. Brit''. p. 180. t. 18. HAB. Hermite Island, Cape Horn, Falkland Islands, and Kerguelen's Land; very abundant. 2. ENTEROMORPHA intestinalis, Link. ''Grev. Alg. Brit''. p. 179. HAB. Hermite Island, Cape Horn; Falkland Islands, and Kerguelen's Land; with the former.

These two species enjoy equally wide ranges with the Ulva latissima. I have found it very difficult to distinguish between this and the former species, even when growing, and between E. compressa and Ulva Linza in a young state. In the Falkland Islands the U. latissima abounds in the land-locked Lagoons, and the U. Linza in the harbours where no heavy seas run; whilst the Enteromorpha compressa, and intestinalis, may be collected on the shores of the weather-beaten coasts. Hence it becomes difficult for the collector to regard these species, whose structure and organization are so similar, as anything more than states of one plant, which commences as a pyriform bladder wherever it germinates, but whose future outline is determined by the depth and tranquillity or the reverse of the element it inhabits, and other natural causes. Such specimens as our Herbaria generally afford, are too often, if not fragmentary, immature; the full development of the species being arrested by the collector, who is content with one entire specimen in whatever stage of growth, and generally preserves it without any note of the conditions under which it was gathered. A few observations on the forms which the Algæ assume during different stages of their growth, would be eminently useful: portions of a crop of such species as this, which often covers shells or pebbles, might readily be transported to other waters, whose state is very different from what the plant enjoyed before. It cannot be doubted that great changes in form would be the consequence; and it is on outline alone that specific characters are chiefly founded.

1. PORPHYRA vulgaris, Ag. ''Grev. Alg. Brit''. p. 169. HAB. Hermite Island, Cape Horn; the Falkland Islands, and Kerguelen's Land; very abundant. This has as wide a range in latitude and longitude as Ulva latissima. 2. PORPHYRA laciniata, Ag. Ulva umbilicata, ''Engl. Bot''. t. 2296. HAB. Hermite Island, Cape Horn; the Falkland Islands, and Kerguelen's Land; very abundant.

Obviously a variety, or rather state of P. vulgaris; of which the P. Columbina, Mont., is probably the young, and P. Capensis, Kütz. another variety.

Frons subcartilagineo-carnosa, vix gelatinosa, undulato-crispata, lobata, e cellulis hyalinis in stratum conglobatis