one or more whorls of involucral leaves; it is sub-cylinrical, slightly sickle-shaped, pale greenish, composed of small oval cells; mouth at first pointed, notched on one side, and finely crenulate; walls much thickened in the lower half from their junction with the calyptra. The fructification is produced in spring and summer, but on account of their firm texture, the colesules remain long after the fall of the capsule, and therefore on fructifying plants are generally found of different ages; size about 2 m. (actual measurement, 2·4+7 mm). Calyptra (fig. 21), when matured campanulate, thickened below, and connate with the walls of the colesule, so that in section the capsule seems to lie in a hollow covered in part by the calyptra, and partly by the dilated apex of the receptacle.

Capsule scarcely of line long, oval, brown, "split to bottom" into four valves. Herr Jack says 80 to 90 per cent. deep ("Botanische Zeitung," Nos. 4-7, 1877).

Spores, according to a list of the relative sizes of spores compiled by Herr Jack" (Botanische Zeitung," Nos. 4–7, 1877), smaller than the majority of other species; they are same size as those of Lophocolon heterophylla, roundish, smooth, brown.

Elaters bi-spiral, broad, long.

Harpanthus Flotovianus was first found by Funck in the Silesian mountains, and distributed by him as Jung. heterophylla, from which it is however abundantly distinct, (in addition to the lateral sub-sessile fructification) in the cellular structure of the leaves, Jung. heterophylla having squarer, smaller areolation, with thicker walls.

It is generally distributed over northern Europe. North America (Drummond).

First collected in Britain by Mr John Sim, of Strachan, on wet rocks, Burra Firth, Uist, Shetland Islands, June 1878. It was from the examination of specimens he was kind enough to forward to me the species was identified.

To the figures by Dr Gottsche, G. & R. Hep. Eur. No. 417, I am indebted for my figures of colesule and cross-section of it; to Dr Carrington, for gift of foreign specimens, and for the following observations :

Note.-Harpanthus scutatus is smaller in all its parts;

Discovery of Harpanthus Flotovianus in Scotland. 447

leaves rounder, more rigid, with smaller thicker walled cells; colour darker olive-brown; acutely emarginate, more concave and sub-connivent.

In a barren state it is difficult to distinguish our plant. from some of the forms of Jung. Bantriensis, and probably on looking over herbaria H. Flotovianus may be found under that name. When fertile the position of the colesule, which in Jungermannia Bantriensis is terminal, will at once lead to identification. In a barren state the thicker-walled hexagonal cells of a duller green colour should serve to distinguish them.

Description of Drawing.-1, plant natural size; 2, x 16; 3 to 9, leaves x 16; 10 and 11, stipules x 30; 12 to 15, stipules x 46; 16, 17, and 18, leaves from foreign specimens x 16; 19 and 20, stipules from foreign specimens x 30, 21, antheridia × 85; 22 and 23, portions of leaf x 290; 24, colesule (after Gottsche); 25, section of colesule (after Gottsche); 26, portion of rootlets x 290.

VIII. On Functional Specialisation of Individuals in Animals and Plants, with Particular Reference to Analogies between the Sertularian Zoophyte and the Flowering Plant. By ALEXANDER DICKSON, M.D., Edinburgh and Dublin; LL.D., F.R.S.E., F.L.S., Professor of Botany in the University of Edinburgh.* (Plate XX.)

In accordance with the custom in this, as in other universities, a newly inducted Professor is expected to deliver an Inaugural Discourse, which may have reference to everything in general or to nothing in particular-which may or may not have specially to do with the subject on which in the course of the session he will have to descant.

Sometimes the glories of the university or of the special chair are referred to at greater or less length. In almost all cases, however, it is difficult to dwell upon such themes. without laying oneself open to the charge of implied selfglorification, as having been deemed worthy of association. with such an institution, or of succeeding such and such

The following formed Dr Dickson's Inaugural Address to the Botanical Class, 5th May 1879, and is printed by request of the Council.

men. As to myself, I need only say that the greater the honour done me, the more acute is the sense of my own shortcomings.

But before leaving this topic, I were alike unmindful and ungrateful were I to omit reference to my dear friend and honoured master, Professor Balfour, who has so long been a power in this university. It is difficult fully to estimate the great influence Dr Balfour has exerted on the scientific training of the multitudes of young men sent forth from this seat of learning. It may perhaps suffice to refer to the very large number of botanists whom he may be said to have created. His energy and enthusiasm have inspired his pupils with a like ardour, while his genial and kindly disposition has endeared him to all. It is to be hoped that his well-earned rest will conduce to that reestablishment of health which his many friends so earnestly desire.

Another and somewhat favourite form of introductory discourse consists in a disquisition on the more obvious and important practical applications of the particular science-what, in fact, may be described as apologies for the subject to be taught from the chair. It seems to me however, that for a scientific man to condescend upon such apologies is not only derogatory to the dignity of true science, but a pandering to that craving for immediate practical application or utility and that short-sighted intolerance of everything else* which are so largely characteristic of the unscientific in this country.

Yet another form of inaugural discourse is that of a general excursion over the domain of the science, noting the more important of its later developments. As, however, my future pupils are, as yet, supposed to know little or nothing of the subject, such intellectual food might

* A morbid condition which has borne such melancholy fruit in connection with one of the principal foundations of the healing art (the science of Physiology), which, in consequence of the ignorant presumption of weak and doctrinaire-though doubtless well-meaning-persons, has by recent legislation been laid under the most pernicious restrictions. Of such persons it may be said that, themselves ignorant, they prevent others from learning. To them may properly be applied the words of Scripture, "Ye have taken away the key of knowledge, ye enter not in yourselves, and them that were entering in ye hindered "

prove hard of digestion; and, as regards myself, another and perhaps weightier reason for the avoidance of such a discourse is that its preparation would have been a somewhat difficult literary labour, which, owing to the recent date of my appointment, I have had neither the time nor the inclination to attempt.

In the circumstances, I have thought it best to give you a somewhat popular exposition of a special subject; and accordingly I have chosen the consideration of some remarkable parallels which may be drawn between the animal and vegetable kingdoms as regards the specialisation of individual forms in the same species for the performance of different functions.

In the first place, I shall refer to the more important conditions as to function which obtain among different groups of animals.

1st. A species may be represented by a single form, each individual being capable of performing all the functions necessary for the economy of the species. This occurs in cases of self-fertilising hermaphrodites, such as certain Lamellibranchiate and Brachiopodous Mollusca.

2d. An advance, in complication, on the foregoing condition is to be found in cases where the species is represented by one hermaphrodite form, but where the reciprocal fertilisation of two individuals is necessary for reproduction, as occurs in snails, &c. This condition may be con

sidered as one leading to

3d. That where the species is represented by two forms. -one, the male, being specialised for the production of spermatozoa; the other, the female, for the production of ova. This condition is the most familiar one, as occurring in all the higher animals.

4th. In certain Cirripedia, the species is again represented by two forms; but here the one is a hermaphrodite capable of self-fertilisation, whilst the other is what Darwin terms a "complemental male," as aiding in the fertilisation of the hermaphrodite. This case is a very remarkable one, as it is, at first sight, difficult to understand the conditions which render necessary the co-existence of male organs in the ovigerous individual along with the same organs in a special male form. The explanation,

however, is probably that suggested by Darwin, viz., that the crossing of distinct individuals, which in many cases is absolutely necessary, may be of advantage even in those cases where it occurs only occasionally.

5th. In some Hymenopterous insects, such as bees and ants, the species is represented by at least three forms: viz., perfect males, perfect females, and females having an imperfect sexual organisation, correlated with important structural modifications. These insects, as is well known, live in associations or colonies, the several forms performing special functions in the economy of the association.

6th. This division of labour-this functional specialisation of individuals so as to constitute a multiplicity of forms-attains its maximum among those organisms termed compound animals. In some of these animals, indeed, we have a specialisation of individuals for almost every conceivable function. For example, in certain oceanic Hydrozoa, there are to be found besides sexual individuals-males and females-also a variety of nonsexual forms, specialised for alimentation, locomotion, protection, &c.

As it is among compound animal organisms that the most remarkable analogies with plants are to be observed, it will be necessary for me to give you an idea of the structure of a compound animal.

A compound animal organism is one where two or more individuals are organically connected with each other. In all such compound or multiple organisms, the compound condition is brought about by a non-sexual process of multiplication termed gemmation or budding. An embryolet us suppose is developed by a sexual process from an ovum. This embryo then produces, by a non-sexual process, a bud or offset, which, though representing a second individual, retains its original connection with the parent. The second individual may similarly produce a third, and the process of gemmation may be repeated to a variable extent, the individual buds all remaining connected with one another. An anatomically united colony is thus formed, which may not unaptly be compared to the colony of bees, only that in the latter case the individuals are anatomically separate from each other.