There are two experimental paths by which the facts relating to organic impurity in water may be approached, the chemical and the biological; and there are two aspects in which these facts may be regarded, the catalytic and the fermentative. The series of observations made in following the one path is the necessary complement of that met with in the other. The path of chemical investigation has been well cleared, and is easily traversed; that of biological inquiry is still beset by many impediments, and is as yet by no means a safe one. It is the object of many recent researches, and of this paper, to lessen these difficulties. The pollution of water with organic substances is inevitably associated with the presence of those organisms whose function it is in the economy of nature to disintegrate such materials. These organisms in their turn are dependent upon organic matter for their continued existence; the Bacteriaceae to which they belong being distinguished from allied forms by an entire absence of chlorophyll, which obliges them to feed only on organic substances. The relation of these two factors of pollution, each to each, is therefore a necessary one; and due regard must in all cases be paid to each in determining the degree of pollution that their coexistence implies

In a paper which I read before the Society in 1879, I gave the results of an investigation I had made with the object of determining the probability, that a man marrying at any age over 40, will, or will not, have children; and I have now extended the same enquiry to men of all ages. The statistics upon which my former conclusions rested, related to- 339 marriages entered into by peers and their near relations, above the age of 40, and were extracted from Lodge's Peerage for the year 1871. For all statistical enquiries this work is, in my opinion, greatly preferable to any of the other works that give records of the British Peerage. The principal ground for this opinion is, that Lodge usually gives the dates of birth of the daughters of each family, as well as those of the sons; whereas other Peerages generally omit those dates, and place the names of the daughters (without any dates) after the names of the sons, so that it is impossible to tell whether they are older or younger than their brothers. In the case of a few families this practice is also adopted in Lodge, presumably by special desire of the head of the family; and it is a matter of regret that this, together with other circumstances to be presently mentioned, diminishes the value of the book for statistical purposes.

The nephridia of Hirudo medicinalis, as is well known to biologists, are in pairs extending from the second to the eighteenth segments (somites). Each nephridium consists of a much convoluted cellular tube. The cells of the tube are perforated by small ducts. The nephridia (“segmental organs”) open externally on the ventral side of the body.

This note describes a peculiar yet interesting form of degenerated Tulipa sylvestris. Last June (1886) the tulip bulbs were removed (after growing and flowering in very rich soil), and set in the December of the same year in a soil of poor quality. The plants did not flower until the present June.

The fact that light was emitted in the dark by a Schizopodous shrimp was first noticed by J. Vaughan Thomson, who, in his Zoological Researches, published about 1820, describes a species which he observed to be luminous under the name Noctiluca. He mentions the presence of scattered spots of red pigment in the animal, but was quite unaware that the production of light was confined to certain definite organs enveloped by this pigment—was indeed unaware of the existence of the organs which form the subject of this paper.

This cell consists of two tubes about three inches long and half an inch in diameter, sealed at one end, and connected together near the closed end by a glass tube about four inches long, having a glass tap in the middle.

When Mr Omond was appointed to the Ben-Nevis Observatory I requested him to take every opportunity of observing what are called Glories—specially noting, when possible, their angular diameters and the order of their colours, so that it might be possible to decide upon the exact mode in which they are produced.

Since the communication of the first of this series of articles to the Eoyal Society of Edinburgh in April, and its publication in the Philosophical Magazine in May and June, the stability or instability of the steady motion of a viscous fluid has been proposed as subject for the Adams Prize of the University of Cambridge for 1888.

Our knowledge of the development of the excretory system in both vertebrates and invertebrates is as yet very incomplete, perhaps more so than of any other system. Until quite recently the whole of the urogenital system of the vertebrates was supposed to be derived from the niesoblast. This view received a sudden check when, on the publication of Graf Spee's researches on the guinea pig in 1884, the segmental (pronephrie) duct was shown to have an epiblastic origin. Hensen, indeed, had noted the fact some years previously, but no notice had been taken of his discovery until Graf Spee called attention to it. Hensen has recently taken up the subject again, and Flemming has published a confirmatory account for the rabbit. Thus there appears no further room for doubting the epiblastic origin of the segmental duct in mammals. It does not necessarily follow that the whole excretory system has an epiblastic origin, but further information is required on the subject. Towards the end of 1886 Van Wijhe demonstrated the epiblastic origin of the segmental duct in Elasmobranchs, and during the present year Von Perenyi has announced that the epiblast plays a similar part in Rana and Lacerta. During the past few months I have been enabled to confirm Von Perenyi's researches so far as Rana is concerned, and have also found that, in regard to the formation of the segmental duct, Teleostean fishes, and probably also birds, are in agreement with other types. The epiblastic origin of the segmental duct is probably a feature common to the Vertebrata generally.

Since my former communications, in which several facts relating to the chemistry of Strophanthus kispidus have been stated, I have completed a systematic examination of various parts of this plant, and more particularly of the seeds. Eeserving a detailed descrip tion of the results of this examination, I propose now to mention only a few of these results in a brief form.

Supposing a tall glass tube open at both ends be cemented into a reservoir packed full of common salt, and the tube then carefully filled up with water, and the whole apparatus immersed overhead in a jar of water, in a few days or weeks (depending upon the length of the tube) particles of salt will arrive at the top of the tube and diffuse into the water atmosphere

The Chairman intimated the foundation by Dr Gunning of the Victoria Jubilee Prize, and the conditions of award which have been approved by the Donor, and added that the Prize of One Hundred Guineas from this source had been this year awarded by the Council to Sir William Thomson, for a remarkable series of papers on Hydrokinetics, especially of Waves and Vortices, forming some of the most valuable that have been communicated to the Society.