The Palæozoic ovule, to which the generic name “Sphærostoma” is now given, was originally described by Williamson in 1877 under the names Conostoma ovale and Conostoma intermedium. He referred sections of different individuals to different species owing to the imperfect condition of the material then available, but expressed the view that Conostoma intermedium “may possibly be a state of Conostoma ovale.” The new material has rendered this interpretation a certainty. With respect to the reference of this ovule to the genus Conostoma, Williamson again expresses some hesitation, merely stating that “it appears to be of the same generic type.” The genus Conostoma was established for an Upper Carboniferous ovule which Williamson designated Conostoma oblongum.

In a paper on “The Pharmacological Action of Protocatechyl-tropeine,” communicated to the Society in 1909, I drew attention to the fact that this substance, when injected intravenously in certain doses produces transient paralysis of the respiration; and I mentioned further that Tappeiner had described a similar temporary cessation of the respiration after the intravenous injection of certain quaternary isoxazol and pyrazol compounds, and of tetra-methyl-ammonium chloride, and Pohl, after the intravenous injection of some quaternary papaverine derivatives. Tappeiner came to the conclusion that the effect was due to stimulation of the terminations of the fifth cranial nerve in the nose; that it was, in fact, of the nature of a Kratschmer-Hering reflex, since he was unable, in the case of methyl-phenylisoxazol-methochloride, to produce cessation of the respiration after anæsthetising the nasal mucous membrane with cocaine; and Iodlbauer, working in Tappeiner's laboratory, also found that anæsthetisation of the nasal mucous membrane prevented the cessation of the respiration produced by tetra-methyl-ammonium chloride. Pohl, on the other hand, was able to produce this temporary paralysis of the respiration after section of the ophthalmic branches of both fifth nerves, and consequently he concluded that the effect was due to an action on the respiratory centre. I came to the same conclusion, since the effect was still obtained with protocatechyl-tropeine after section of both fifth nerves in the base of the skull and after section of both phrenic nerves, and was not synchronous with the effect on the circulation or with the paresis of the nerve-endings in the muscles of the hind limbs. Further work with tetra-methyl-ammonium chloride, however—my stock of protocatechyl-tropeiue being exhausted,—showed that the effect was in large measure peripheral and due to a transient paresis of the nerve-endings in the respiratory muscles.

The collection of Nereidæ brought home by the Scotia proves to be of considerable interest. As other expeditions have indicated, the family is but poorly represented in the antarctic or sub-antarctic regions; and although a large number of specimens were collected at the South Orkney Islands, these have all proved to belong to one species, N. kerguelensis M'Int. No nereids were obtained at any of the deep-water stations farther south—the family being decidedly littoral in its range.

The chief interest, however, lies in the material collected so assiduously throughout the vessel's wanderings. Six other species were obtained, including one from the Falkland Islands, hitherto undescribed.

In an Appendix to the Actiniæ of the Challenger Expedition, R. Hertwig. 1882, described a peculiar genus, Porponia, with two species, P. elongata and P. robusta, which he characterises in the following manner: “Actiniarien (Hexactinien?) mit 2 Schlundrinnen ohne Ringmuskel, mit dünnwandigen Tentakeln, deren Basen auf der äusseren Seite durch spangenförmige Verlängerungen des Mauerblatts gestützt werden.” Partly owing to the badly preserved material, however, he did not venture to indicate definitely its systematic position, though he considered it conceivable that it represented a transitional form between the Zoanthidæ and the true Actiniæ, or Hexactiniæ.

The first of this series of papers, that on the “Fossil Plants collected during the sinking of the shaft of the Hamstead Colliery, Great Barr, near Birmingham,” was published in 1888, and the second, dealing with the “Fossil Flora of the Coal Field of the Potteries,” in 1891.

Since that date the North Staffordshire Coal Field has been re-surveyed by members of the Geological Survey, and the result of this re-examination of the geology of the Potteries Coal Field was the classification of the strata into several well-defined groups.

The genus Bathydoris was created by Bergh in 1884 in his Report on the Nudibranch Mollusca collected by the Challenger. In his account of the anatomy of the new genus Bergh draws attention to the anomalous combination of characters possessed by the animal, and gives it an annectent position between the Dorids and the Tritonids, but places it among the Dorids on account of the predominance of Dorid features. The single specimen of Bathydoris abyssorum was dredged off New South Wales in 2425 fathoms. A second specimen of this peculiar genus was obtained by the Danish Ingolf Expedition and described by Bergh in 1900. This specimen came from 1870 fathoms in Davis Strait, and resembled B. abyssorum, with specific variations. Thus Bathydoris came to be regarded as an isolated genus with the characters of a connecting link, and appropriately a denizen of deep water. Our anatomical knowledge of the animal is derived almost entirely from Bergh's accounts of the two species mentioned, and is moderately extensive, considering the rather imperfect state of preservation of the material and the fact that he was dependent on single specimens in each case.

1. It may be taken as conclusive that the final distribution of stress at rupture point in a member subjected to an external bending moment is a rectangular one, unless where the cohesion of adjacent layers is not sufficient to withstand the shear induced by the resisting moment of the section.

2. That, provided shear does not take place, the neutral axis moves always to the position which reduces the summation of the tensile and compressive stress areas, across a section, to the equilibrant of the external forces. (In the case of a beam this reduces to zero; in that of a hook, at the principal section to the suspended weight.)

3. That the total resisting moment of these stresses must be equal to the external bending moment as measured to the neutral axis at rupture point, but that these balancing moments do not differ materially from those measured to an axis obtained by dividing the sectional area into tensile and compressive stress areas which are in inverse proportion to the magnitude of their respective ultimate direct stresses.

The advantage of these formulæ are important. It is possible to indicate with certainty the magnitude of the load which will cause rupture in a beam or a hook provided there is known the point of application or the effective arm of the load, the cross-section of the beam or hook, and the breaking strengths of the material when subjected to the different forms of direct loading.

During the Scottish Antarctic Expedition of 1892–93 Dr W. S. Bruce secured fœtuses of Stenorhynchus leptonyx and Lobodon Carcinophaga, and on his return passed them over, with other material, to Professor D'Arcy W. Thompson for the Zoological Museum of University College, Dundee. While some of the material has unfortunately been lost sight of during these twenty-one years, one specimen, viz. that of a fœtus of Stenorhynchus leptonyx, was still in existence, and was returned by Professor D'Arcy Thompson to Dr Bruce, who in turn asked me to examine and report upon it. Furthermore, during the voyage of the Scotia embryos of Leptonychotes weddelli were obtained by the Scotia naturalists, and these were passed on for description to Professor Waterston, at that time in the University of Edinburgh. It is on this material that the present monograph is based.