KNOWLKDGi:. 



Decemiier, 1912. 



prodiictiun of injurious compounds such as dihydroxy- 

 stearic acid. 



Comparative experiments with steamed and unhealed soils 

 showed that poorer growths were obtained with the former, and 

 from this the inference is drawn that the production of 

 injurious substances outweighs that of the beneficial com- 

 pounds, and that until the former arc eliminated it is not 

 possible to ascertain to what extent steaming may be 

 beneficial. 



Conclusions of a similar character are drawn by Messrs. 

 Lyon & Hizzell in a paper communicated to the Eighth 

 International Congress of Applied Chemistry (Original 

 ComiiiHiiications, lyl2, XV, 159), in which the results 

 of re-iuoculafing steamed soil with fresh and with heated 

 soil are described. 



At first the best growth of plants was obtained on soil that 

 had been inoculated with fresh soil, but this did not continue. 

 The ln.\nriance of growth appeared to depend not so much 

 upon the available nutritive substances present as upon the 

 amount of toxic compounds produced by the steaming, and 

 this factor varied w-ith the nature of the organic substance in 

 the original soil. Aeration of the soil and the growth of 

 plants both reduced the toxic character of the steamed soil, 

 but the speed of oxidation was not always a measure of the 

 rate at which the soil ceased to be toxic. 



GEOLOGY. 



By G. W. TvKKEi.L. A.R.C.Sc, F.G.S. 



STR.ATIGRAPHV AT THF, BRITISH ASSOCIATION. 

 — .As might have been expected, Scottish stratigraphy bulked 

 largely at the Dundee meeting. Two important announce- 

 ments were made of the discovery of fossils in the hitherto 

 barren Highland Border Series. This is a narrow band of 

 crushed shales, cherts, grits, and calcareous beds, occasionally 

 with igneous rocks, occurring at intervals along the Highland 

 Border fault from .Arran on the West to Stonehaven on the 

 East Coast of Scotland. The fossils have been discovered by 

 Dr. T. J. Jehu near .Aberfoyle, and by Dr. R. Campbell at 

 Craigeven Bay, near Stonehaven. In the .Aberfoyle district, 

 between Loch Lomond and Callander, the Border Series is 

 separated by a line of thrust from the Leny Grits (Dalradian) 

 to the north, and by a reversed fault from the Lower Old Red 

 Sandstone to the south. The fossils have been found in 

 muddy films in grey chert bands, one to three inches thick, 

 and consist, as determined by Dr. B. N. Peach, almost 

 entirely of hingeless brachiopods belonging to the following 

 genera: — Acrotrcta, sp. ; Lingiilella, sp. ; ? Obolus, sp. ; 

 Obolella, sp. ; and Hattened chaetae of Polychaetc worms. 

 This assemblage indicates that the series is probably of 

 Upper Cambrian age. 



The Border Series near Stonehaven consists of crushed 

 spilitic lavas with intercalated black shales, jaspers and 

 cherts. In August, 1909, Dr. Campbell, with Drs. Peach 

 and Gordon, succeeded in finding fossils in the black shales. 

 Mr. Tait, of the Geological Survey of Scotland, subsequently 

 made a detailed search in the fossiliferous beds, and the 

 material obtained by him, submitted to Dr. Peach for 

 determination, yielded the following forms : — Lingulella, 

 Obolella, Acrotrcta, Linarssonia, Siphniotrcta; a bivalve 

 phyllocarid allied to Caryocaris and Lingiilocaris ; and 

 cases of a tubicolar worm. Since graptolitcs are absent 

 from this assemblage. Dr. Peach believes that it indicates an 

 Upper Cambrian, rather than an Ordovician age. The 

 Border Series is here separated from the Dalradians by a 

 reversed fault, and is overlain unconformably by strata of 

 Downtonian age. 



Dr. R. Campbell also described his recent researches in the 

 Downtonian and Old Red Sandstone of Kincardineshire. The 

 rocks now assigned to the Downtonian are a series of vertical 

 or highly-inclined strata, three thousand feet thick, consisting 

 of breccias, mudstones, shales, volcanic conglomerates and 



tuffs. These strata h.ive yielded Dictyocaris in abundance, 

 also Ccratiocaris: Archidcsinus, sp. ; a new genus of 

 Myriapod ; Eiirypteri ri, sp.. nov. ; and plates of a new 

 Cyatliasffis. The volcanic conglomerates indicate that the 

 volcanic activity destined to play so large a part in the history 

 of the succeeding Old Red Sandstone, had already been 

 initiated in Upper Silurian times. 



The highest beds of the Downtonian pass up conformably 

 into the micaceous sandstones and conglomerates of Stone- 

 haven, which are considered as the base of the Lower Old 

 Red Sandstone in this area. The latter consists of a great 

 thickness of coarse conglomerates and sandstones, with lavas 

 and tuffs. The recognition of certain well-marked volcanic 

 zones has been of assistance in working out the stratigraphy. 

 The lavas include dacite, hornblende-biotite-andesite, augite- 

 andesite, hypersthene-andesite, hypersthene-basalt.and olivine- 

 basalt. Minor intrusions occur in the form of dykes and sills 

 of quartz-porphyry, biotite-porphyry, dolerite, and lampro- 

 phyre. The coarse conglomerates which form so large a part 

 of the succession may be divided into two groups ; those 

 built largely of quartzites and other Highland rocks ; and 

 those consisting mainly of volcanic rocks — the volcanic 

 conglomerates. 



Further excavations among the Cambrian rocks of Comley, 

 Shropshire, are described by E. S. Cobbold. These have 

 disclosed green sandstones of Lower Cambrian age in Comley 

 brook, in which fossils characteristic of the Oleiicllus lime- 

 stone of the district have been found. A Middle Cambrian 

 breccia has also been discovered largely composed of debris 

 of the above-mentioned sandstone, but the matrix of the 

 breccia has yielded a Pa mil oxides fauna new to the district. 



MRRO.SCOPV. 



i;y F.R.M.S. 



NOTE ON PREPARING FLIES' TONGUES FOR THE 

 MICROSCOPE. — The short-horned Diptera possess a singu- 

 larly beautiful organ in their tongue or proboscis — either 

 appellation is justifiable — produced by the fusion of two 

 lateral maxillae. The chitinous cuticle or skin is studded with 

 numerous sclerites or hard pieces, usually of a dark brown 

 colour ; and these sclerites occur in several series, some 

 constituting supports for the organ, some the bases of the 

 sucking pad on each side, and some the C-shaped supports for 

 the canals which traverse its under surface. The transition 

 from one of these series to another is not abrupt ; the 

 accompanying figures show the passing of the basal sclerites 

 into those of the canals. In a typical fly there are three 

 series of basal sclerites, central, anterior, and posterolateral. 

 The central ones are in many species partly modified into the 

 organs which have been described in the pages of Science 

 Gossip as " Flies" Teeth " ; these alternate with sclerites 

 supporting the junctions of the canals. The terminal canals 

 frequently give off secondary canals, and therefore are 

 distinguished as anterior and posterolateral. These may be 

 well seen in Mr. Senior's excellent photograph. Figure 270 in 

 our June number. In the picture of Callipliora I'oiiiitoria 

 {see Figure 501), the four broader black bands at the base 

 represent the " teeth," though their free extremities, shaped like 

 chisels with a triangle taken out of the edge, are not here in focus. 

 In many genera, though not in all, there are several rows of 

 these teeth, placed one behind the other. Internally they have 

 muscles attached to them ; and it may be remarked that two 

 kinds of striated muscle are to be found in the proboscis of 

 most flies ; the arrangement of the musculature being very 

 complex. Its main attachments are to the posterior 

 transverse median sclerite, its accessory, the posterior 

 lateral, and the inferior basal : these will be noticed 

 as prominent black marks crossing the suctorial surface 

 in Figure 270. It is necessary to give names to these 

 pieces of chitin. as they occur with great regularity in 

 the different groups of flies, sometimes one, and sometimes 

 another, being especially developed or reduced. In Doli- 

 chopiis, for example, the central basal sclerites are fused, 



