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ABSTRACT LONDON. Royal Society, March 30.—Sir Charles Sherrington, president, in the chair.—The late W. G. Ridewood: Observations on the skull in foetal specimens of whales of the genera

Megaptera and Balaenoptera. Five foetal skulls were described. The presence of an interparietal bone in some whales, and the meeting of the parietals in a median suture in others, is of

little use in taxonomy. Syncondyly is associated with suppression of the atlanto-epistropheal joint. There is no separate foramen for the hypoglossal nerve. The periotic bone shows no

separate centres of ossification, but a diffuse endpchondral granular deposit. The orbitosphenoid ossifies independently of the presphenoid. In whales there is no “external pterygoid plate”

of alisphenoidal origin; the alisphenoid is the ossified ala temporalis. The growth of the malleus and of the tympanic bone, and the relations of the great bulla to the primary annulus

tympanicus, were described.—W. L. Balls: Further observations on cell-wall structure as seen in cotton hairs. The daily growth rings consist of large numbers of fibrils, spirally arranged,

with frequent reversals of the direction of the spirals. This arrangement is predetermined for the secondary cellulose of the growth rings by the initial pattern laid down in the primary

wall. The individual fibrils have a cross-sectional area of the order of 0-05 square microns. Some of the evidence suggests stereo-isomerism in cellulose.—L. T. Hogben and F. R. Winton: The

pigmentary effector system. I. Re-action of frog's melanophores to pituitary extracts. The posterior lobe of the pituitary gland contains a specific stimulant which, if injected into

the frog, brings about a condition of general and complete expansion of the dermal melanophores. A minute dose induces a darkening of the skin readily visible to the naked eye. The pituitary

melanophore stimulant is not destroyed by pepsin or boiling. It is rapidly destroyed by trypsin but not so quickly by acid hydrolysis. After cocaine, curare, atropine and apocodeine it

still evokes its characteristic response, and therefore acts directly upon the melanophores. The results confirm the endocrine significance of the condition of general pigmental contraction

found by Allen and others to follow removal of the pituitary gland in tadpoles.—Agnes Arber: On the development and morphology of the leaves of palms. The leaf-stalk is the basal or proximal

region of the true petiole while the “fan” or “feather” limb is a modification of the distal region of the true petiole. The complex plication of the limb arises through the development of

a series of invaginations penetrating the leaf-stalk tissue between the bundles. The “ligule” and “dorsal scale” of the fan-palms represent adaxial and abaxial distal margins of the

uninvaginated proximal region of the petiole. The palm leaf, as a whole, is a petiolar phyllode with a pseudo-lamina.—H. E. Roaf: The acidity of muscle during maintained contraction. Records

of electrical changes by a manganese dioxide electrode in combination with a calomel electrode show that: (a) In a veratrinised muscle the acidity remains as well as the tension. (6) In

decerebrate rigidity reflex inhibition is accompanied by a decrease in acidity. Thus acidity and tension are related and a single mechanism is sufficient to account for both tetanus and

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