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1. A lipid-teichoic acid complex was isolated from Streptococcus faecalis N.C.I.B. 8191. The covalent nature of the linkage between teichoic acid and lipid was established. 2. The complex exhibits macromolecular properties in solution, and ultracentrifugation studies show that these are due to micelle formation. 3. From chemical studies it is concluded that the teichoic acid is a poly(glycerol phosphate) in which some of the glycerol hydroxyl groups possess kojibiosyl [2-O-alpha-d-glucopyranosyl-(1-->2)-alpha-d- glucopyranosyl] substituents, together with d-alanine ester residues. 4. The lipid is 1-kojibiosyl diglyceride, already known as a membrane component of this organism, with probably a phosphatidyl substituent. The phosphatidyl kojibiosyl diglyceride is attached to the teichoic acid through a phosphodiester linkage, and the chain of the teichoic acid contains 28-35 units. 5. Although the complex represents the whole of the membrane teichoic acid in this organism, only about 12% of the membrane glycolipid is associated with teichoic acid. 6. Two phosphatidyl glycolipids, closely resembling that bearing the teichoic acid, were isolated from the lipids of the organism and were partly characterized.

SummaryCoexisting calcium-rich and calcium-poor pyroxenes have been separated from the gabbros and ferrogabbros of the Skaergaard layered basic intrusion and chemically analysed. Nine new analyses of augites, three of inverted pigeonites, and one of orthopyroxene are presented, together with optical properties. The trend of crystallization of the augites is different from that drawn by previous investigators. The stages at which the orthopyroxene and pigeonite begin and cease to erystallize are defined, and the sub-solidus exsolution and inversion textures of the pigeonites are examined in detail. The characters of the exsolution textures and the degree of pigeonite inversion (monoclinic to orthorhombic pyroxene) are shown to change gradually with height in the intrusion, and are related to a gradual change in the interval between the temperatures of crystallization and inversion.

The origin of the Newer Granites is long-standing problem. In the Caledonian orthotectonic zone the intrusions span the period of late orogenic convergence and uplift, but attempts to relate them as a group to late Iapetan subduction have been unsuccessful. A range of rock types is represented, mainly with I-type affinities, and granodiorite is the most voluminous. In contrast, granitic intrusions south of the Moniaive shear zone in Scotland and also in the north of England have significant S-type characteristics, span the trace of the Iapetus suture and have ages in the range 400-390 Ma, significantly younger than intrusions to the north. We refer to these younger granitic intrusions, along with others of similar character along-strike to the southwest, as the Trans-Suture Suite. We explore the link between the Trans-Suture Suite and recently recognized orogen-wide sinistral transtension in the Early Devonian period. Importantly, the Trans-Suture Suite intrusions are accompanied by an intense suite of lamprophyre dykes, the origin of which is to be sought in extension, decompression and heating of enriched Avalonian sub-continental lithosphere. In some instances the granite intrusions carry clots of lamprophyric origin and the Criffel body is particularly important in being continuously zoned from an I-type with lamprophyric enclaves to an S-type interior. We propose that generation of these lamprophyres during transtension advected heat into the base of the crust to produce the S-type component of the Trans-Suture Suite. Modelling presented shows that generation of voluminous S-type magmas requires the coincidence of several factors: hydrated sub-continental lithospheric mantle preserved during 'soft' collision under the Trans-Suture Suite zone; thermal relaxation to remove any subduction refrigeration; crust composed of juvenile volcanogenic material; and Devonian transtension. Our models suggest that if hydration pre-dated transtension then only small granitic bodies could be produced, unless the zone of lamprophyre generation extends beyond the rift zone. The emplacement of the Trans-Suture Suite intrusions overlapped the Acadian deformation period that succeeded the transtensional episode during which the granite magmas were generated.

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