The observations which were made in Loch Earn during August 1911 and described in the Trans. Roy. Soc. Edin., vol. xlviii, p. 629, demonstrated that in that loch there was during autumn a fairly definite temperature or density discontinuity, and suggested that the loch was a peculiarly suitable one in which to observe in greater detail the boundary waves occurring at the discontinuity. The previous investigation had for its main purpose the demonstration of the existence of standing oscillations at the discontinuity, and in that was entirely successful. The observations showed, however, that in addition to the primary standing oscillations there were other less regular movements about which the observations gave little information, as they were not made at sufficiently close intervals of time.

In the year 1900 Bretscher (1) published a short account of a new aquatic Oligochæte belonging to the family Naididæ, which was assigned by him to a new genus, Hæmonais, under the name H. waldvogeli. Its chief peculiarity lay in the complicated blood-vascular system, to an account of which Bretscher devotes about half of his description. No further account of any representative of the genus has since appeared.

Some months ago I was surprised to find, in Lahore, specimens which were certainly referable to the same genus as the Swiss worms, though manifesting a few differences, sufficient to distinguish them as a separate species. Since my first discovery of the present form I have had the advantage, which did not fall to Bretscher's lot, of being able to observe sexual individuals; and as the worms are remarkable in other respects than that of the vascular system, and since moreover the somewhat curt description which he gives is perhaps scarcely sufficient to satisfy legitimate curiosity in regard to a new genus, I give below a fairly complete account of the Lahore specimens.

The common forked setæ which constitute the ventral setal bundles in the Naididæ possess, like the simple setæ of many of the earthworms, a slight swelling on the shaft, the so-called nodulus. The setæ themselves are the principal organs of locomotion, being used as levers, which obtain a hold of the substratum by means of their hooked and forked distal ends; and besides being movable in an anteroposterior direction they are capable of some degree of protrusion and retraction. The position of the nodulus on the shaft is held to regulate the distance to which the seta can be protruded; though it can be retracted so that the nodulus is below the level of the epidermis, it cannot be protruded beyond that degree which brings the nodulus level with the surface.

The Naididæ are a family of small fresh-water Oligochæta, in which the usual mode of reproduction is the asexual, by fission; sexual forms are, in general, rare, and in the majority of species, and in some whole genera (e.g. Slavina), they have not so far been observed at all. Records of the genital organs are therefore of interest; and if they were available throughout the group it can hardly be doubted that we should be able to judge better of the affinities of genera and species, and consequently to improve our classification; since the diagnoses of species and genera, and the scheme of classification, depend at present to an unduly large extent on one single set of characters, the form and distribution of the setæ.

The study of sexual individuals of the genus Dero has resulted also in the discovery of the curious phenomenon of the atrophy of the alimentary canal at sexual maturity; this occurs also in Hæmonais (v. ant.); it has not hitherto been found elsewhere in the Oligochæta, though it is known to occur (apparently in a less extreme form) in a number of Polychætes.

In the investigation of a remote and isolated island for mineral and metalliferous deposits its geological structure and the character of the rock masses of which it is formed are of primary importance. Where the evidences of metalliferous deposits are more or less openly and widely exposed the geological structure, while still of interest, is not so important. Ore deposits, as a rule, occur in rock-bodies which have definite relations to each other, a characteristic geological structure.

In the island of South Georgia, where the exposed evidences of metalliferous ores are very slight, the investigation of its rock-bodies, their character and geological structure, is a necessity. By making an examination of that kind, we endeavour to ascertain if there may be concealed ore-bodies which further exploratory prospecting may with a reasonable probability expose to view.

The special interest of South Georgia depends on its evidence regarding the geology of the part of the Southern Ocean which lies south of the South Atlantic. According to Professor Suess, the island is an extension of the Andes, which, at the southern end of South America, turn eastward, and by a great horse-shoe-shaped curve pass through South Georgia to the South Orkneys and Graham Land.

The geology of South Georgia is but little known. Thürach † described the island as consisting of metamorphic rocks, ranging from granular gneiss to clay-slate, and of diabase tuff.

The first petrographic description of the rocks of South Georgia was given by H. Thürach in 1890, as part of the results of the German Scientific Expedition to that area of 1882–83. He described the rocks as clay-slates interstratified with phyllite and phyllite-gneiss, with quartz-phyllite, calc-phyllite, and quartzite-slate. He also mentions a great development of interbedded schalsteine or diabase tuffs, and describes a rolled pebble of “korniger gneiss.” His phyllite-gneiss is said to contain tourmaline, apatite, and andalusite. He emphasises the great crushing and disturbance the rocks have undergone.

I have no information regarding the gametophyte, nor have I examined the structure of axis and leaf in young plants. It must therefore remain to be seen what light such data may throw upon the problem of the phyletic place of Deparia Moorei. The nature of the stele, the leaf-trace, and the venation, in very young plants, would also present points of value. But it will be at least evident that the vascular system of the axis is, in mature plants, of an advanced type, and it may reasonably be affirmed that the marked variability in the degree of dictyostely is an index of an inherent plasticity. It seems reasonable to suggest that the reductions in size, and simplification of structure in the direction of solenostely shown in fig. 40, is related to the cultural conditions. The plant from which the material was derived had lost ground both in size and healthiness of its leaves.

The study of Organic Form, which we call by Goethe's name of Morphology, is but a portion of that wider Science of Form which deals with the forms assumed by matter under all aspects and conditions, and, in a still wider sense, with Forms which are theoretically imaginable.

The study of Form may be descriptive merely, or it may become analytical. We begin by describing the shape of an object in the simple words of common speech: we end by defining it in the precise language of mathematics; and the one method tends to follow the other in strict scientific order and historical continuity.

1. The active ingredient of the poison of the Abor and Mishmi poisoned arrows is, in some of them, aconite, and, in others, croton oil. The former, apparently, is generally used by the Mishmis, and the latter by the Abors.

2. Although sufficient botanical materials have not been obtained to identify the species of aconite, the nature of the pharmacological action suggests that the species is one containing relatively more pseudo-aconitine than aconitine and, therefore, more resembling Aconitum ferox and A. heterophylloides than A. Napellus.

3. The arrow-poisons containing aconite were found to be much more lethal in warm-blooded animals than those containing croton; but the aconite-poisoned arrows that were examined carried usually too little aconite for a single arrow to produce death in man, even if the whole of the poison should be quickly absorbed.

4. The arrow-poisons containing croton, on the other hand, were found to be incapable of producing death in warm-blooded animals by the absorption of the poison into the circulation, and could do so only tardily by rendering the animal more susceptible to septicæmia, following inflammatory and even necrotic changes in the tissues into which the poison had been inserted.

5. While thus relatively inert in warm-blooded animals, and presumably, therefore, in man, the croton arrow-poison is extremely toxic in cold-blooded animals, being for them one of the most lethal of poisons, readily absorbable into the circulation and producing irritation and hæmorrhages in parts remote from the locality of insertion, and the latter, especially, in the alimentary canal. Remote effects may be produced even without any obvious evidence of local irritation in the place into which the poison has been inserted. These remarkable peculiarities in the action of the Government of India arrow-poison are reproduced by its ether extract and by the oil of Croton Tiglium.

6. Excepting failure to cause general action in warm-blooded animals, it is interesting to note that in many of their important effects, croton arrow-poisons as well as croton oil reproduce the effects of viperine venoms.