LONDON. Royal Society, April 30.—Sir William Crookes, O.M., president, in the chair.—Prof. B. Moore: The presence of inorganic iron compounds in the chloroplasts of the green cells of plants, considered in relationship to natural photo-synthesis and the origin of life.—Dr. J. C. Willis: The lack of adaptation in the Tris-tichaceæ and Podostemaceæ.—R. P. Gregory: The genetics of tetraploid plants in Primula sinensis. The paper describes results of experiments with two giant races of Primula sinensis, which have been shown to be in the tetraploid condition—that is, the plants have 4x (48) chromosomes in the somatic cells and 2x (24) chromosomes in the gametic cells, whereas in the ordinary (diploid) races of the species the numbers are 2x (24) and x (12) respectively. The result of most general interest is the discovery that reduplication of chromosomes has been accompanied by reduplication of series of factors, so that, whereas in the diploid zygote each factor is represented twice, AA; in the tetraploid zygote it is represented four times, AAAA; and there are three distinct hybrid types, namely, AAAa, AAaa, and Aaaa. The reduplication is made manifest by the occurrence of F2 ratios in the form 15D: 1R, when in the diploid races the ratio is 3D: 1R. This result recalls those obtained by Nilsson-Ehle in oats and wheat, and by East in maize, but in the tetraploid Primulas the reduplication affects not merely the factors for isolated characters, but all the factors which it has been possible to study,—J. A. Gunn: The action of certain drugs on the isolated human uterus. It has been found that the involuntary contractile tissues (such as the heart, intestine, and uterus) of mammals can be kept exsected in Locke's solution at ordinary room temperatures for many hours, while still retaining the power of executing normal rhythmic movements when subsequently placed, under the proper conditions, in oxygenated Locke's solution at body temperature. With this knowledge, it is possible, without difficulty, to perform experiments on certain isolated human tissues, removed in the course of surgical operations; and those experiments can be made under similar conditions to, and therefore entirely comparable with, experiments made on corresponding tissues of those mammals ordinarily used for investigation. In this paper this method of investigation has first been utilised to determine the response of the isolated human uterus to certain drugs.—D. J. Lloyd: The influence of osmotic pressure upon the regeneration of Gunda ulvae. G. ulnae, is capable of living indefinitely in water having an osmotic pressure of more than 2 and less than 33 atmospheres. The rate of regeneration of the posterior end in G. ulvae depends on the osmotic pressure of the medium. This osmotic pressure has an optimum value for regeneration at 18 atmospheres, i.e. just below that of sea-water, and limiting values at 5 and 33.5 atmospheres. Restoration of lost parts in G. ulvae is brought about entirely by the undiffer-entiated parenchyma cells which migrate to the region of the wound and build up the lost parts.—Surg.-Gen. Sir D. Bruce, Major A. E. Hamerton, Capt. D. P. Watson, and Lady Bruce: (a) Glossina brevipalpis as a carrier of trypanosome disease in Nyasaland. (b) Trypanosome diseases of domestic animals in Nyasaland. Trypanosoma pecorum. Part iii.—Development in Glossina morsitans.—H. E. Armstrong and H. W. Gosney: Studies on enzyme action. XXII.—Lipase. (IV.).—The correlation of synthetic and hvdrolvtic activity.