according to Mr. F. O. Bower, (“Jour. Mic. Sc.,” Jan., 1880,) is partly formed by invagination, and partly by deliquescence. In Adenocystis, too, these conceptacles are as wide at the mouth as at the base; but in most, if not in all the Fucaceæ, the aperture of the fertile conceptacle is much narrower than the interior. The conceptacle of Adenocystis, therefore, may be homologous to the “Fasergrübchen” of Alaria esculenta and Fucus platycarpus. (Vide Keutz. “Phycologica Generalis,” p. 92.)

When young, the frond of Adenocystis is dotted over with tufts of colourless hairs, which encircle the mouths of the conceptacles. A transverse section through the bladder-wall of a not fully matured specimen, shows the frond to be covered with short clavate bodies, in which the cell contents are aggregated together into several distinct masses. It is to these Hooker refers, when he says that “the frond is coated with a thin layer of vertical clavate articulate filaments.” A section through the frond of a mature specimen shows it to be covered with three different kinds of bodies:—

• (a.) A number of short clavate filaments, similar to those already mentioned.

• (b.) Somewhat longer jointed hairs, probably developed from (a).

• (c.) Oval sacs, containing zoogonidia (?)

These are all represented in fig. 1.

The plant is a common annual, found chiefly in tidal pools. It cannot be obtained during the months of June, July, and August.

8. Ecklonia radiata.

The generic description in the “Handbook of New Zealand Flora” is: “Root scutate or dividing into short fibres. Frond olive-green, pinnatifid, ecostate, segments produced from the magnified teeth of a simple lamina, which is contracted to a solid or inflated stem at the base. Sori superficial on the lower part of the pinnæ of narrow ellipsoid spores, mixed with clavate inarticulate filaments.” (Sp. radiata:) “Frond 1–2 feet long, stem solid or sparingly inflated.”

The stem consists of three tissues: an epidermal layer of coloured cells, a second layer of parenchymatous tissue, and a third of loose cells, lying in mucilage. In the second tissue, just beneath the epidermal cells, there is a circular ring of longitudinal “secretion canals,” which probably act as conducting or storing vessels for the mucilage, for when a fresh stem is cut through, mucilage exudes from them in considerable quantity. These canals are formed by the splitting away of adjacent cells, and appear first as small irregularly shaped openings in the tissue, some distance from the apex of the frond. As they increase in

size, they are cut off from the surrounding tissue by a ring of small cells. The third tissue consists of anastomosing filaments which have no particular direction with regard to the axis of the plant.

Reproduction by zoogonidia, developed in sporangia,^* closely packed together on the lower portions of the frond. The “clavate, inarticulate filaments” of the Handbook are probably young sporangia. I have not as yet been able to see the zoogonidia escape. It is worthy of notice that the sporangia are developed in corresponding patches on both sides of the frond.

Common, just below low water-mark.

9. Macrocystis dubenii.

Description in Hooker's “Handbook of New Zealand Flora” (Generic:) “Root branching, giving off immensely long, slender, simple stems, which bear leaves at the surface of the water. Leaves formed by the continual splitting of a primary terminal leaf, developed in secund order along the lengthening floating stem, each lanceolate, serrate, ribless, undulate, with a pyriformoblong or sub-cylindric bladder at its base. Spores superficial on submerged radical leaves, forming clouded sori, ellipsoid with a hyaline coat, surrounded by densely-packed inarticulate paranemata.” (Sp.) “Stems, 50 to perhaps 700 feet long or upwards. Fronds extremely variable in length and breadth, 2–4 feet long, 2–6 inches broad, ciliate-serrate.”

It is wrongly here stated that the stems are simple. They branch dichotomously, but only immediately above the rhizoid. The length of the stem has been variously stated; and it is generally said to be the longest plant in the world. In Lyttelton Harbour, however, it certainly does not attain a greater length than 70 feet; commonly it is from 20 to 30 feet long. In structure the stem is very similar to that of Ecklonia. The secretion canals are present, and originate in the stem, at some distance below the apical leaf. In the “Transactions of the New Zealand Institute,” vol. xiv., p. 562, it is said: “Professor Parker exhibited and made remarks upon sections of the stem of Macrocystis, showing sieve tubes like those of Cucurbita.” This doubtless refers to the anastomosing cells of the central tissue, which sometimes closely resemble the sieve tubes of Cucurbita, as figured by Sachs.

The bladders are formed by the central tissue ceasing to grow, whilst the external tissues develope rapidly; and, consequently, the stem at this point swells outward, and at last tears apart the filaments of the central tissue, which are left hanging

round the interior of the bladder wall. Fig. 3 is a transverse section through the external tissues of the stem.

Reproduction by zoogonidia, produced in clavate sporangia on the basal leaves. Fig. 4 is a transverse section through a fertile portion of the frond. The sporangia, however, are much more densely crowded together than there represented.

Distribution, everywhere abundant, forming a fringe round the coast; rhizoid fixed below low water-mark.

10. D'Urvillea utilis.

Generic description in “Handbook of New Zealand Flora:” “Root scutate. Frond stalked, dark olive-brown or black, flat, expanded, very thick and coriaceous, or honeycombed transversely internally, palmate or pinnate without distinct organs. Fruit diœcious, conceptacles scattered over the whole frond in the cortical stratum, containing either obovoid subsessile spores or branched filaments bearing ovoid antheridia.” (Sp.) “Frond dark-brown or black, often 30 feet long, forming an immense flabellate palmately-lobed laciniated lamina contracted at the cuneiform base into short stipes as thick as the wrist, segments or thongs often 1 inch thick, honeycombed internally.”

The epidermal cells of this plant are much larger than in most brown seaweeds. The central tissue is composed of longitudinal fibres, which occasionally anastomose.

Reproduction: The plant is diœcious. The conceptacles have not a fringe of hairs surrounding the aperture, as in Fucus platycarpus, and many other Fucaceæ. The reproductive organs may be found almost at any season of the year, but they are best obtained in the winter months. It is stated in Hooker's Handbook (vide ante) that the spores (oospheres) are subsessile. This may be the case in young conceptacles; but in the maturer ones the oospheres are developed on branched hairs. Fig. 5 represents one of these branched hairs, bearing several empty and one mature oogonium, with a tripartite oosphere. This is an important exception to the rule that unbranched hairs alone are found in the female conceptacles. Fig. 5, a, b, c, show the method of division of the oosphere.

At low tide, on a warm moist winter's day, many of the fronds of D'Urvillea, if examined, are seen to be covered with hundreds of little dark-brown almost black papillæ, consisting solely of oospheres expelled from the conceptacle. The antheridia do not collect outside the conceptacle in such numbers as the oospheres, but they occasionally form whitish dots covering the surface of the frond. The antheridia are developed in the usual way on branched hairs.

Hab. Common about low tide-mark, on exposed rocks.

11. Notheia anomala.

Description in Hooker's Handbook (generic): “Frond, olive-

green, parasitic, filiform, irregularly branched, proliferous, solid, with distinct stem and branches, but no bladders or leaves. Conceptacles scattered over the whole frond under the surface, containing linear-obovate spores, and simple paranemata.” (Specific:) “Fronds 3–8 inches long, growing from the conceptacles of Hormosira, excessively branched, bushy, cylindric; branchlets narrow, spindle-shaped, axis of solid interwoven filaments, periphery of radiating coloured filaments.”

This is undoubtedly a true parasite, as it is never found elsewhere than on Hormosira banksii. It generally grows out of one of the conceptacles of its host, but occasionally out of the solid portion of the stem, when it never penetrates deeper than the cortical tissue. True parasitism is very rare among the Fucoideæ. One or two cases in the Phæosporeæ are mentioned by Decaisne and Le Maout. This is the only one with which I am acquainted amongst the Fucaceæ.

Reproduction: The plant is diœcious. I have not seen the male conceptacles; and here it may be noticed that, in all the New Zealand Fucaceæ, female specimens are very much more plentiful than the male. The female conceptacle contains unbranched hairs; but there are no long hairs surrounding the aperture of the conceptacle. The oogonia are developed in the ordinary way; but the number of oospheres in each oogonium appears to vary from about 7 to 11; but, as I have had no opportunity of examining fresh specimens of this plant, I am not quite sure about this point. Fig. 6 shows several oogonia.

Hab. In tidal pools, on Hormosira; not uncommon, to some extent sporadic.

12. Hormosira banksii.

This has been fully described by Mr. Mollet. (“Trans. N.Z. Inst.,” 1880, Art. xxxix.)

13. Splachnidium rugosum.

Description in Hooker's Handbook (Generic:) “Root, a disk. Frond olive-green, cylindric, proliferously branched; branches saccate, full of mucilage and branched filaments; walls thin, membranous. Fruit diœcious. Conceptacles scattered over the whole surface of the frond, attached to the inner surface of its walls, spores linear-oblong, subsessile, paranemata simple.” (Specific:) “Fronds, 4–8 inches high. Main axis stout, cylindric or club-shaped; ¾ inch in diameter; branches sac-like, truncate, 1–2 inches long, surface covered with mamillæ, each furnished with a pore that opens into the spore cavity beneath.”

The stem consists of an epidermal tissue of small coloured cells surrounding a mass of mucilage, into which protrude a number of long branched hairs. The top of the growing stem is covered with a slight down, composed of very peculiarly-shaped colourless hairs, made up of a number of cells which are

converse on one side and nearly straight on the other. These cells are sometimes filled with granular matter, which may be forced out by a slight pressure. As the antheridia of the plant have never been observed, it is just possible that these hairs may be antheridial in function.

Reproduction: Plant diœcious. The conceptacle is surmounted by a ring of hairs, and in its interior contains a number of unbranched hairs. The oogonia are obscurely pedicelled, and developed on the cells lining the wall of the cavity. Each oogonium gives rise to a large number of oospheres, thus differing from all other Fucaceæ that have hitherto been described. Each oosphere is very small, compared with the oospheres of any of the other Fucaceæ. Fig. 7 shows several oogonia.

Hab. An annual, common on tidal rocks.

14. Cystophora.

I have no remarks to offer upon this genus.

19. Carpophyllum maschaloearpum.

In this plant I have noticed antheridia developed from the surface cells of the conceptacles. Mr. F. O. Bower has noted the same in another genus of Fucaceæ.

20. Marginaria boryana; M. urvilleana.

Hooker's description is (Generic): “Frond olive-green, unilaterally, flabellately pinnate. Leaves, bladders, and receptacles distinct. Leaves sub-confluent with the stem, dichotomously semi-flabellate, vertical. Bladders in series, on the upper margins of the leaves. Receptacles in series with the bladders, unilateral, sub-simple, terete or compressed, containing spherical conceptacles with obovoid spores.” (Sp. boryana:) “Frond many feet long, naked below; pinnæ linear, very long, ⅙–¼ inch broad, ribless with hooked serratures. Bladders elliptic-obovoid, as large as a hazel nut, sub-apiculate. Receptacles cylindric, 1 inch long, acuminate, simple or sparingly spinous. (Sp. urvilleana:) A smaller plant than boryana, but hardly distinct specifically; the pinnæ are a foot long, gradually dilated, simple or flabellately branched on one side. Bladders smaller, sub-spherical, not apiculate.”

I have only seen a few specimens of this genus; but since the two species as figured by Montaigne in the “Voy. au Pole Sud” are evidently male and female plants of a single species, there is probably only one species, subject to a few slight variations.

The stem consists of three tissues, but presents no peculiarities.

Reproduction: Plant diœcious. I have only seen female conceptacles, which are of the ordinary typical form. It is