(4th.) The Confervacea are widely separated from the Sphæroplea by both Sachs and Bennett; but these two orders differ only in their mode of reproduction, whilst they closely resemble each other in general structure and appearance.

It seems to me that the principal cause of error in these two classifications is the idea that all the Oosporea must be closely related, for behind this idea is the belief that fertilization has arisen only once in the vegetable kingdom; that is to say, that all plants which are reproduced by fertilization are descended from a common stock. But this scarcely appears to me to be correct, for fertilization has evidently arisen independently in the animal and vegetable kingdoms, as it is not found in the Protozoa, or the Palmellacea, the lowest divisions of each kingdom. Again, looking at the Alga themselves, we see that fertilization is not the same process in all. The oospheres of Fucus, for example, differ considerably from the oospheres of Vaucheria; but, at the same time, the structure of the stem in the two genera is totally dissimilar. Now, it is much easier to suppose that fertilization has arisen independently in these two groups, than that they have diverged from a common ancestor, reproducing itself in this way. For it can scarcely be doubted that fertilization first originated in conjugating zoospores. We have only to suppose (and the supposition is perfectly warrantable) that an advantage was gained by a specialization of the functions of the two cells; the one increasing in size and becoming passive, the other remaining small and motile, since it would have to penetrate into the interior of its companion cell. Through some such variation as this, fertilization might easily have arisen on various occasions.

One more objection might be taken to Sachs' classification of the Alga. He has included the Characea under the Carposporeæ ; though it appears probable that they should stand by themselves. Perhaps they are degenerate forms of a higher type; for it is only in habit and, to some extent, in structure of stem, that they at all resemble the Alga; and we know that many freshwater plants have become much simplified in structure (e.g. Marsilia and many of the Naiadea). A plant living in water has no need for a stem built up of many tissues. The simplicity of the stem of Chara does not necessarily therefore connect it with the Alga, and its reproduction, on the other hand, can scarcely be compared with that of the Floridea and Coleochatea. Professor Sachs has endeavoured to trace out homologies between the two, which, however, to me appear to be far-fetched and doubtful. It is much easier to suppose that the Characea is an order standing by itself, than to consider it as allied either to the Alga or the Musci. Mr. Bennett has well dealt with this question in the "Journal of Botany," 1878, p. 202; so it will not be necessary to go into any detail here.

The genealogical tree on Plate XA. seems to me to show, as nearly as our present knowledge will permit, the genetic affinities of the different orders of the Alga. Of course, much of it is provisional and somewhat doubtful. For example, I have placed the Palmellacea as the lowest group, but this position may belong

As a lineal classification of the Thallophytes is impossible, I would tabulate them thus, the orders of the Alga being given in full:

To illustrate

to the Chroococacea. Again the Myxomycetes are placed in the vegetable kingdom; but there is no more reason for placing them there than in the animal kingdom. The position of the Conjugatea, too, is very doubtful, and it seems not unlikely that the Zygneme will have to be separated from the Diatoms and Desmids. Fertilisation I conceive to have originated in four different orders: the Fucacea, the Canobia, the Sphæroplea, and the Siphonea. (These are underlined.)

ART. XLIX.-Observations on the Fucoidea of Banks Peninsula. By R. M. LAING, M.A.

[Read before the Philosophical Institute of Canterbury, 6th August, 1885.] Plate X.

THE brown seaweeds must always be an interesting group of plants to the botanist, on account of the exceptional facilities they offer for the investigation of the phenomena of fertilisation. and sexual reproduction. The New Zealand genera are especially attractive, because of their great diversity of form and structure.

The first collection of these was made by Mr. Menzies, surgeon to Captain Vancouver's expedition. All his specimens. are from Dusky Bay, in the south-west coast of Otago. They were described about the end of the last century. Prior to this time, however, a few marine Alga, common to New Zealand and other southern regions, had been incidentally named by previous visitors to the Australasian seas. Banks and Solander had roughly described one or two of the more conspicuous species. The first systematic collection, however, was made between the years 1821 and 1825, by Bory, one of the naturalists of the French ship Coquille. He described about a dozen species of the Fucoidea from various parts of New Zealand. He was followed by Messrs. Lesson and Richard, naturalists of the French ship Astrolabe. They contributed three or four new species to the list of those already known. A considerable number of specimens obtained during the second voyage of the Astrolabe were described by Montaigne in 1845; and about 1840 a very large collection of New Zealand plants was made by Sir J. Hooker, botanist to the Erebus and Terror expedition. The Fucoidea obtained by him, to the number of about fifty, were described in Flora Nova Zelandiæ."

But by this time a large synonymy had grown up around the nomenclature of the New Zealand seaweeds, partly owing to the same species being described from different coasts under different names, and partly owing to the independent description of collections sent home to English and continental naturalists. Agardh, Turner, Kuetzing, and Lamoureux had all at various times described and named species of seaweeds found in the