ALBERT

Description: 101 Rhode Island Red × Light Sussex chickens have been made to conform to four differently shaped growth-curves from hatching to 24 weeks, by control of their plane of nutrition. The four treatments HH, LH, HL and LL allowed comparisons to be made between birds of the same age but different weights.As the main concern has been to find the essential nature rather than the precise extent of the effects produced by different planes of nutrition, the treatment differences were made as extreme as possible without allowing the rations to become unbalanced.The conclusions reached are as follows:1. The treatments used have produced marked effects on the growth-curves of the birds, analysed on the basis of equal age. These effects have been shown to be statistically significant at all stages after 3 weeks.2. In body-weight and form, two types of bird were produced. The HH and LH birds were similar, with greater relative proportions of the late developing parts and secondary sexual characteristics, and the small differences that existed between them were not significant at 24 weeks. Likewise, the LL and HL birds formed a comparable group, exhibiting a more infantile body form similar to that of the HH and LH birds at an earlier age. The differencebetween the HL and LL birds, though generally not statistically significant, is greater than that between the LH and HH group.3. The treatments produced a small but consistent effect on the external measurements of the birds when comparisons were made on the basis of equal weight. Nine measurements were recorded. In the case of four measurements, no treatment effect was noted. Four skeletal measurements demonstrated a consistent effect of treatment, the LL and HL measurements exceeding those of the HH and LH at equal live-weights. This result was reversed in the case of the only muscular measurement, thickness of leg musculature. Opposite results are therefore indicated for the muscle and skeletal tissues. This finding will receive further discussion when the dissection analysis results are discussed in a later paper.4. The presence of definite growth-gradients from the body extremities towards the trunk is indicated by the external measurements.5. The two sexes differ in their live-weights at equal age and in their bodily proportions both at similar ages and similar weights. The most marked sex-difference in external measurement is noted in the length of the mid-wing, and a possible functional explanation is advanced. In general, the sex-difference is greatest for the late maturing characters.

Description: Study of the fauna from a newly discovered fossiliferous outcrop of the Cove Lower Marine Band in Thornton Burn, East Lothian, has led to the correlation of this horizon with the Redesdale Ironstone in Northumberland and has thereby demonstrated the first palaeontological link between the Upper Calciferous Sandstone in S.E. Scotland and the Lower Limestone Group in N.E. England. The collection of D1 fauna made from the Thornton Burn outcrop includes goniatites, brachiopods, lamellibranchs, and crinoids. The discovery of Beyrichoceratoides redesdalensis (Hind) gives the first definite indication of the presence of B zone in the Scottish Carboniferous. Faunal lists and descriptions of some of the more interesting species are included in this paper as well as descriptions of the crinoids collected which are given in the succeeding paper by James Wright.

Description: Kinematic analysis of tension gashes in an exposure of the Moine Series indicates that the fractures resulted from a tectonic movement directed from north to south, unrelated to that responsible for the nearby Caledonian Moine Thrust.

Description: The conditions under which ptygmatic veins develop occur when the country-rock—as in a granitized area—is locally less competent or more yielding than quartzo-felspathic magma which may intrude it. Veins therefore which are being driven forward by pressure from behind, will buckle plastically if they encounter a resistance during injection, and a succession of such buckles will produce a typical ptygmatic vein. The amplitudes of the flexures so formed depend on the relative physical states of the vein and host-rock; so for any particular vein there is usually a more or less constant size for the tortuosities developed. The mechanism explains several features observed in examples of ptygmatic veins, and has been reproduced experimentally in the laboratory. The contortions are therefore not necessarily due to the deformation of the veins by post-injection flowage or tectonic movements of the country-rock.

Description: A zone of intense metamorphism extends for six feet on both sides of a nearly vertical fifteen feet wide olivine dolerite dyke. Adamellites have been converted in situ to rocks resembling quartz porphyries, and mobilization of cordierite gneiss has been effected. Petrography and chemical analyses show that metamorphism is not purely thermal. Although little actual fixation of doleritic “end liquors” took place in the wall rocks the cause of these remarkable contact effects is ascribed to hydrothermal activity near the “blind end” of the dyke.