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.

When two jets or streams of water moving with equal or unequal velocities meet at an angle and combine to form one common stream, the impact is usually accompanied by loss of energy, which may be large if the velocities are high. If the jets are free (exposed to air on every side), the pressures are unaltered by impact, and the loss may be readily calculated in terms of the initial velocities and angle of inclination, by an application of the equations of energy and of momentum. Where the streams are confined before and after impact—as, for example, where the streams outflowing from the impeller of a centrifugal pump impinge on the more slowly moving body of water in the volute, or where the two streams combine in the mixing chamber of a jet pump or injector,—both pressures and velocities are altered by the impact, and the available data are insufficient to enable the magnitude of the losses to be predetermined from a priori reasoning.

The Entomostraca recorded here were collected by the S.Y. Scotia on its way to and from the Antarctic, and also while carrying on investigations there during the years 1902 to 1904. The Entomostraca in these collections belong chiefly to the Copepoda, but the Cladocera and Ostracoda are also represented, the last by a considerable number of species. These three groups are described below in the order mentioned.

To determine whether the diurnal variation in body temperature is due to the combined effects of the various influences which are known to act upon it, such as muscular exercise, the ingestion of food, sleep, etc., or is present independently of these, the daily routine of the individual who is the subject of the experiment may be reversed artificially by causing him to work during the night and rest and sleep during the day, or it may be modified in another way, viz. by rapidly changing his longitude in a journey from west to east, or vice versa. If the temperature of the body is dependent on the influences mentioned, then a total reversal of the daily routine, or any modification of it, should produce a corresponding change in the diurnal temperature curve.

During the past few years probably no group of fossil plants has received more attention from palæobotanists than that of the Pteridospermeæ. Many fern-like impressions, derived from Carboniferous rocks, have proved to be members of this division of the vegetable kingdom; while many more may ultimately be removed from the Filicales and included in the Pteridospermeæ. Specimens, however, in which the internal structure is preserved, may, as a rule, be correctly referred to their respective class, but among those included in the latter group there is considerable diversity of organisation, and recently described genera have tended to increase the diversity of type rather than to indicate relationships among the forms already known.

Although the amount of active research that has been carried on during the past few years on the question of chromosome reduction and relative problems has been very great, the nuclear activities here concerned are still far from being understood. We are not yet in a position to draw general conclusions in regard to meiotic phenomena. It therefore seems to me desirable that all observations of fact and rational interpretations should be placed on record, so that when it becomes possible to generalise, all lines of evidence may be available.

My first knowledge of Stenomyelon Tuedianum was derived from a microscopical preparation in the collection of the late Mr C. W. Peach, A.L.S., which, through the kindness of his son, Dr B. N. Peach, F.R.S., subsequently came into my possession. The specimen was labelled as having been found “near Berwick.”

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.

There are a number of gaps which exist in our knowledge of the temperature changes which occur in fresh-water lakes. The broad lines on which the changes occur are fairly well known, but on almost every point there is a lack of detailed knowledge, and every investigation shows new problems requiring attack. One of the most interesting of these problems is the causation of the temperature seiche, and the effect of varying meteorological conditions. The problem is a difficult one, as the factors to be taken into consideration are so numerous, and the data from which to form conclusions are difficult to procure. We must first obtain an accurate knowledge of the changes which are occurring in the body of water under consideration—not only at one point but at all points, and this necessitates observations at frequent intervals of time, at numerous depths, made from several points on the surface of the loch. As yet there are no satisfactory self-recording instruments by means of which we can record the temperature of water at a considerable depth below the surface, and recourse must be had to the reading of mercury thermometers.

The Cephalopoda collected by the Scotia may, with a few trifling exceptions, be separated geographically into three divisions, coming respectively from South Africa, South America, and the Antarctic.

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 material placed at my disposal for the purposes of this paper comprised the brains of four adult specimens of the Weddell seal, in addition to the brain of the young animal which has formed the subject of my former contributions. The four adult brains having been removed at the time the animals were killed, and preserved in a solution composed of spirit (90 per cent.) 6 pints and formal (2 per cent.) 4 pints, were, with one exception, in a firm and satisfactory condition for detailed anatomical examination. The body of the young seal had been preserved with a view to ordinary dissection, and therefore its brain was not in the firm state of the adult specimens; but as I had the opportunity of removing this brain from the skull, I was able to observe the disposition of the dura mater to the hemispheres of the cerebrum and cerebellum. While the dura mater presented, as a whole, its usual arrangements, it was noteworthy that the falx cerebri did not act as a septum between the two hemispheres of the cerebrum except to a very slight extent, and certainly for not more than one-third of the distance between the vertex of the cerebrum and the dorsal surface of the corpus callosum. As a result, in the region referred to the opposing mesial surfaces of the two hemispheres lay not only in close apposition with each other, but their convolutions were intimately adapted to each other. Similarly, the tentorium cerebelli only extended a short distance between the cerebrum and the cerebellum, and, as the occipital ends of the cerebral hemispheres fell considerably apart from each other, there was space for the accommodation of the well-developed vermis of the cerebellum as well as for the bulbous pineal body, which occupied a position upon its dorsal aspect. As I removed the brain from the skull the stalk of the pineal body gave way, and probably the same thing had occurred during the removal of the adult brains, for, while different lengths of the stalks had been preserved, there was only one complete specimen of its bulbous extremity. Looked at from the vertex, the general outline of the whole brain was that of a four-sided figure with rounded angles, and the cerebral hemispheres concealed the cerebellum except where the vermis was exposed between them at their occipital ends. The frontal ends of the hemispheres were not rounded into frontal poles; but, on the contrary, they almost formed flat frontal surfaces. Similarly, the occipital ends were rounded and not pointed to form occipital poles. There was a small amount of difference in the absolute size of the adult brains, and the largest specimen measured 120 mm. in its fronto-occipital diameter ; 115 mm. in its greatest transverse diameter at a point well forward on the temporo-sphenoidal lobes; and 71 mm. in vertical height, measured from the pons varolii to the vertex of the cerebrum. Thus, apart from the peculiarity of its general outline in total size, it was only slightly less than an average human brain. Throughout the anterior two-thirds of their extent the cerebral hemispheres were, as already indicated, in very close apposition, and the falx cerebri only dipped into the pallial or superior longitudinal fissure to a slight extent; but in its posterior third this cleft opened to form a wide interval, measuring 65 mm. in the transverse direction at its hinder end and narrowing as it ran forwards towards the posterior end of the corpus callosum. In the deep level of this interval the pineal body and the upper surface of the vermis were visible, as well as part of the upper surface of the cerebellar hemispheres. It should be stated that the backward extension of the occipital lobes of the cerebrum carried them 2 mm. beyond the cerebellar hemispheres.

In its essential features the basal aspect of the brain conformed to current descriptions of the mammalian brain ; but it presented many special points of interest, to which reference will be made in the course of my survey.

On a recent occasion, looking into a small shallow pool near Lahore, I saw here and there on its bottom a reddish appearance, which a closer examination showed to be due to innumerable worms, implanted by one extremity in the mud, and waving their free ends in the water. These were the Limnodrilus described below. A quantity of the mud taken for further examination yielded, though in very much smaller numbers, three other Oligochætes, viz. Branchiura sowerbyi, Lahoria hortensis, and a species of Dero.

Recent investigations have profoundly modified our conception of the value of the histological elements of the nervous system. Conflicting opinions are still held on many points of primary importance, perhaps the chief of which is the relation of the nerve fibre to the nerve cell. The origin of the nerve fibre is a problem of vital interest not only to the embryologist, but also to the physiologist and the pathologist. It has long been the subject of controversy, and, in spite of numerous valuable researches, we are still far from knowing the relation of the nerve fibre to the central neuroblast, a relation of essential importance in the understanding of all neuro-pathological questions.

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.

The specimens submitted for examination were:

(a) Portions of the brain (labelled Specimen XXXI.).

(b) Portions of spinal cord (labelled Specimen XXIV.).

Both were in excellent condition as regards fixation and hardening, having been preserved for many years in a fluid composed of formol and 95 per cent. alcohol (the fluid was also injected into the cerebral vessels). They were, previous to histological examination, submitted to the following processes:—

i. Comparatively thin slices were taken from various regions and placed for twenty-four hours in absolute alcohol.

ii. Then transferred to acetone for twelve hours.

iii. Placed in xylol until permeated.

iv. Embedded in paraffin of melting-point 52° C. Sections were then taken with an improved form of the Cambridge rocking microtome, and fixed to slides by means of the albumen method.

So far as regards number of individuals, and their size, this is one of the largest collections of Ascidians brought back in recent years from Antarctic seas. It contains almost exactly the same number of species of Ascidiacea (Ascidiæ Simplices + Ascidiæ Compositæ) as the Discovery collection—viz. fifteen or sixteen—but whereas in the latter collection nearly all the species were represented by single specimens, in the Scotia collection most species can show long series of individuals—in all there are about two hundred specimens, as against the thirty-three brought home by the Discovery.

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.

In an account of the Jurassic flora of Sutherland, published in 1911, it was stated that a few petrified specimens from Eathie Bay, Cromarty, and from Helmsdale on the coast of Sutherland, would be dealt with in a subsequent paper. One of the best preserved of them forms the subject of a recent communication to the Royal Society of London. The majority of the specimens described in the following pages are from the Hugh Miller collection in the Royal Scottish Museum, Edinburgh. We take this opportunity of expressing our thanks to the Director of the Museum for the loan of the fossils, and for permission to have sections prepared for microscopical examination. For the loan of the section reproduced in Plate II. fig. 19 we are indebted to the generosity of Dr Kidston.