The present communication deals with the Nemertines of Millport and its vicinity, the study of which occupied part of the time I spent at the Millport Biological Station during May and June 1909. The material was not completely worked out during my stay there, and most of the section-cutting was left till after my return to India. I wish to acknowledge here the uniform courtesy and kindness which I received from Mr R. Elmhirst, the Superintendent of the Station, to whom my thanks are due for the readiness with which he placed the resources of the institution at my disposal, and for help in other ways.

The following paper contains an account of certain of the littoral Oligochæta of the Firth of Clyde, found at and near Millport on the Island of Cumbrae, and at Wemyss Bay on the mainland. The investigation was begun during a two months' stay at Millport, from May to July, 1909, at which time I was working in the Marine Biological Station there, and it was completed after my return to India. I have to thank Mr R. Elmhirst, the Superintendent of the Station, for his constant kindness, and for the courtesy with which he placed all the appliances and resources of the Station at my disposal.

Les Mousses rapportées par l'Expédition nationale antarctique écossaise ne sont pas très nombreuses, mais elles présentent cependant de l'intérêt, parce que la plupart proviennent de localités qui étaient restées jusque là totalement inexplorées. Le plus grand nombre des espèces a été récolté à lîle Gough ou Diego Alvarez, dont la florule bryologique était tout à fait inconnue; les récoltes de M. le Dr R. N. Rudmose Brown nous ont fourni 21 espèces pour cette petite île. Dix espèces ont été recueillies à l'île Laurie, l'une des Orcades méridionales, dans la région antarctique proprement dite; enfin, 6 espèces proviennent de l'Ascension.

The seeds of Peganum Harmala contain two alkaloids, Harmaline and Harmine. The pharmacological actions of the former alkaloid have been described in a previous communication to this Society; in this paper an account is given of the pharmacology of the second alkaloid, Harmine.

Harmine (C13H12N2O) was discovered by Fritche in 1847. Apart from a few observations by Tappeiner, its pharmacology has not been investigated. Tappeiner states that, in mammals at least, the general nature of poisoning by harmine is qualitatively the same as by harmaline, but that the former alkaloid is weaker in action. He found that a dose of 0·2 gramme per kilo of harmine is fatal to the guinea-pig in about 12 hours, while the same dose is fatal to the rabbit in about 1 hour, and that a frog is killed in about 7 hours by a dose of 0·03 gramme (per kilo?). He states further that there appears to be one qualitative difference between the actions of the two alkaloids, in that harmine produces paralysis of reflex excitability before arrest of the heart. It may be stated here that this does not constitute a qualitative difference between the actions of harmaline and harmine, because the same effect is produced by harmaline.

Some time ago the author published the results of a series of experiments on the flow of water through tubes having uniformly diverging boundaries, in which the loss of energy corresponding to given angles of conicity of the tubes was determined. These pipes, some circular, others square or rectangular in cross section, had the same initial and the same final areas, these being respectively the same as those of circles of 1·5 inch and 3·0 inches diameter, the ratio of initial to final mean velocity of flow being in each case 4 to 1.

The first step made in this investigation was the recognition of increased specific electrical conductivity as a general characteristic of photochemical action. It was argued that if there be any common characteristic in photochemical changes it must be found in the simplest as well as in the more familiar and more complex reactions which are characteristic of the metabolism of plants.

No chemically simpler case suggested itself than the increase in electric conductivity of crystalline selenium under the influence of light. This change might indeed be held almost to lie outside the range of chemistry proper, and to belong to the class of change often spoken of as merely physical change. But no sharp line can be drawn between physical and chemical changes, and the clue proved most useful.

The recent important work of Farmer and Digby (1910) on the cytology of certain varietal and hybrid ferns has raised again the interesting and absorbing question of the mechanism of mitosis. This paper constitutes a valuable addition to the literature which has bulked so largely during the last few years, and which has been instrumental in establishing many interesting and important facts regarding the greatest of all cytological problems—namely, nuclear division. The interest of this later contribution lies, not so much in the actual observations which these writers have jointly recorded—although the facts revealed are important in that they confirm the work of other writers and extend the range of observation,—but rather in the theory which they have deduced from their results and which they have put forward to account for the factors at work in the living cell,—factors which they believe to be concerned in the formation of the achromatic spindle.

While collecting specimens of Diplolabis römeri (Solms) at Pettycur about three years ago, I discovered several blocks of stone containing numerous petrified fragments of another Zygopterid fern—Metaclepsydropsis duplex (Williamson). Two of the blocks were found to be parts of one large mass, and the petrifactions could be traced from the one block into the other. In size the complete mass must have been about 3 feet × 2 feet × 2 feet. The larger portion had to be broken into two before it was possible to remove it. Another block containing similar specimens was obtained later, but the preservation was so poor that the whole of the material was discarded.

In my former contribution I gave a general summary of the animal under consideration, and discussed in detail the peritoneal arrangements of its abdominal cavity and the naked-eye anatomy of its alimentary organs. In the present paper I shall give an account of the genito-urinary system.

The kidneys were situated on each side of the dorsal mesial mesentery. Each was covered on its ventral aspect by the peritoneum forming the dorsal wall of the greater peritoneal sac. The right kidney was quite free from contact with the liver and the duodenum, while the left kidney was equally free from contact with the spleen. Both kidneys were therefore situated well back towards the pelvic end of the abdominal cavity. Each kidney measured 5 inches in the longitudinal diameter and 2 inches in the transverse diameter. The hinder or caudal end of each reached a point two inches from the pelvic inlet, which, as formerly described, was narrow and well defined by the course of the hypogastric (umbilical) arteries.

In a large class of engineering structures it is essential that the materials employed should be both strong and ductile, so that not only shall the structure be able to resist heavy loads, but that if by any chance it is overloaded it shall not collapse suddenly. In order to ascertain whether a metal is suitable for a particular structure, its strength and ductility are determined experimentally. The test most commonly in use consists in applying a gradually increasing pull to a bar of the metal until fracture takes place. The maximum load supported per unit of the original cross-sectional area of the bar is called the tensile strength or tenacity of the metal, and the elongation of an initial measured length, expressed as a proportion of that length, is called the extension, and is used as an index of the ductility of the metal.

The first three parts of this work, on the skeleton and muscles, were published in the Transactions of the Society in 1905, 1907, and 1909.

In 1905 I briefly drew attention to the existence of vascular papillæ on the afferent branchial arteries of Myxine, which had up to that time escaped notice, and which I then described in the following words: “In addition to the definite bloodvessels, Myxine possesses a system of large lacunar spaces, such as the extensive subdermal cavity, the spongy tissue of the head, the peribranchial sinuses, etc., which have been generally regarded as belonging to the lymphatic system. I have, however, long been convinced that these spaces were in communication with the blood vascular stream.