At 25°, in oxygen at 600 mm. pressure, and in presence of water-vapour at a pressure of less than ·1 mm., the only product of oxidation of phosphorus trioxide was found to be phosphorus tetroxide, P2O4. The latter was identified by microscopic investigation of its crystals as well as by quantitative analysis.

It is now universally recognised that, at least to as close an approximation as is practically testable under given conditions, a match in hue can be established in normal colour-vision between any visible light and a mixture of three suitably chosen spectrum lights. The latter are selected usually from portions of the spectrum in the close neighbourhood of three definite wave-lengths. Though considerable variation in the choice of these three standard lights is possible, it is found to be most suitable to place them in the pure red, the pure green, and the pure blue regions of the spectrum respectively.

The geometry associated with the double binary (2, 2) form has, previously, been exhaustively treated by Mr Kasner and Professor Turnbull by regarding the form as representing the twisted quartic: namely, the complete intersection of a sphere (more generally a quadric) and a quadric, and projectively as the bicircular quartic. A full list of references will be found in the paper of Professor Turnbull in the Proceedings of the Royal Society of Edinburgh, xliv (1924), 23–50. More recently Dr Vaidyanathaswami has investigated further properties of the cyclic, using a new canonical form for the (2, 2) curve.

1. Degeneration of the germinal epithelium of the testis invariably follows the operation of vasoligation or of vasectomy in the mouse, but does not become evident until a considerable period of time has elapsed.

2. Similar degeneration follows the operation of epididymo-deferentectomy, but after a much shorter interval of time.

3. This degeneration is caused perhaps by the pressure within the seminiferous tubules exerted by the accumulation of seminal products, or more probably by the action of toxic substances liberated from the disintegrating cell and sperm debris.

The aim of the present paper is to extend Daniel Bernoulli's method of approximating to the numerically greatest root of an algebraic equation. On the basis of the extension here given it now becomes possible to make Bernoulli's method a means of evaluating not merely the greatest root, but all the roots of an equation, whether real, complex, or repeated, by an arithmetical process well adapted to mechanical computation, and without any preliminary determination of the nature or position of the roots. In particular, the evaluation of complex roots is extremely simple, whatever the number of pairs of such roots. There is also a way of deriving from a sequence of approximations to a root successive sequences of ever-increasing rapidity of convergence.

In the theory of radiation recently advanced by Sir J. J. Thomson it is supposed that electromagnetic waves and quanta are both present in a beam of light. The quanta, which are responsible for the photoelectric effects, are closed rings of electric force propagated in the direction normal to the plane of the ring. Professor Whittaker has discussed this conception from the point of view of Maxwell's equations, and has shown that it is consistent with them ; or rather with an extension of them in which a magnetic density μ analogous to the electric density ρ is introduced.

The object of this note is to place on record the existence of a specimen which demonstrates the one-time existence of poisonous serpents of hitherto quite unheard-of dimensions.

The specimen, shown in the text-figure, is a poison-fang remarkable for (1) its enormous size, and (2) its curvature. As regards size, the fang measures nearly 65 mm. along the outside of the curve, and 46 mm. in a

straight line along the chord of the curve. It measures close to but clear of the swollen base 11·4 mm. in diameter and 35 mm. in circumference.

In a paper recently communicated to the London Mathematical Society the present author showed that the characteristic numbers an and bn of the Mathieu equation—

may be developed, for large positive values of q, in the forms

If we consider a set of values a0, an, a–n and a set of equidistant points x = a, a±nw, there are many interpolation formulæ which give functions assuming the values a0, an, a–n at the points x = a, a + nw, a − nw respectively. The function with which the present note deals is, writing π/w = m,

1. Following upon a previous study of spirit specimens of Glyptonotus, observations have been made on live examples of Chiridotea cœca and C. tuftsii with the object of elucidating points relating to the natural history and structural peculiarities of the Glyptonoteinæ.

2. Though wholly carnivorous, Chiridotea is not a predaceous animal. Subsisting on portions of animals, already dead, which it discovers by persevering search aided by sense of smell, it is a scavenger rather than a hunter of living prey.

3. The uncommon division of the thoracic limbs in Chiridotea is associated with an exceptional range of locomotor accomplishments. The animal not only walks and swims like other members of the Idoteidæ, but also tunnels its way for long distances under the surface of sand.

4. The three pairs of gnathopods subserve a number of functions. They are used in ordinary reptant progression. They are used to seize and hold on to food, but not to tear or rend it. Working in conjunction with the mandibles, they play an essential part in the process of manducation. They also come into action during sand-tunnelling.

5. On closer observation the characteristic type of limb-taxis of Chiridotea proves to be specially related to the tunnelling habit. During the process of tunnelling the mesially situated gnathopods and pleopods, working together, deal with one body of sand, the laterally projecting peræopods with another.

6. Certain common features in the bodily conformation of Serolis, of Apus, of Limulus, and of Trilobites are interpreted as an adaptation, by convergence, to a habitat on the surface of mud.

7. Owing to the transparency of its body, the movements of the alimentary canal of Chiridotea can be observed during ingestion and the movements of the hepatic cæca during digestion of food.

8. The midgut exhibits, according to circumstances, two different types of peristaltic movement. At the very commencement of a meal, and also during long continued vain effort to masticate a tough morsel of food, a succession of forward-running waves of contraction is observed. When food begins to be swallowed these are replaced by backward-coursing waves of contraction.

9. There are two pairs of hepatic cæca. As the midgut fills the more mesial pair passes out of sight. The laterally situated cæca increase greatly in volume and exhibit a series of dilatations or pockets, which enter into vigorous and long-sustained rhythmic contraction.

10. The mesial split in the thoracic sternites is a device for allowing distension of the body after a meal.

11. Its eyes being wholly dorsal, Chiridotea shows no conspicuous colour change in response to its background. It has both brown and black chromatophores, the latter contractile.

12. A new point of specific difference between C. cœca and C. tuftsii is recorded.

13. The direction of rotation by which the uropods of Valvifera have assumed their present orientation is discussed anew, the conclusion again being that the anterior border was originally mesial.

14. Objections are raised against the elevation by Racovitza and Sevastos of the northern representatives of Miers' Glyptonoteinæ to independent sub-family rank.