October 17, 1912J 



NATURE 



egg-packet of Pterygotus. The conclusions of the 

 author were confirmatory of those of Sir VV. Dawson 

 and Prof. Penhallow tiiat it was vegetable, and after 

 boiling in nitric acid, the presence of spores within 

 the carbonised tissue was demonstrated. In attempt- 

 ing to form some conception of the original structure 

 and shape of Parka, the author concluded that the 

 original spore-containing tissue was almost flat, not 

 spherical, and unlike any known sporangia of to-day. 

 There was, certainly, intimately connected with it a so- 

 called "indusium." In the discussion. Dr. G. Hick- 

 ling stated that his independent observations on Parka 

 were in very close agreement with those of Mr. Don. 

 He questioned, however, the nature of the cells, 

 hitherto regarded as spores, and preferred to consider 

 them as constituting simply a parenchymatous mass. 

 These masses possibly served as reproductive buds 

 analogous to the gemmae of the Hepaticae. Dr. 

 Newell Arber (Cambridge) remarked on the extreme 

 interest of Mr. Don's careful work on Parka, and was 

 quite prepared to allow that the organs termed spores 

 were undoubtedly of that nature. He differed from 

 Dr. Hickling's criticisms, and pointed out that if 

 these bodies were not spores, but parenchymatous 

 cells, they certainly could not have survived the ex- 

 tremely severe chemical treatment to which they had 

 been subjected. Dr. Hickling appeared to have 

 e.xamined chiefly spore sacs in which the spores were 

 not yet mature, a condition also commonly noticed 

 in some of Mr. Don's specimens, and this appeared 

 to have been the chief basis of his criticism. Dr. 

 .'\rber agreed w-ith Mr. Don that Parka was un- 

 doubtedly a member of the ThalIophyt», and very 

 possibly an alga. 



The first results of investigations on the contents 

 of the Millstone Grit of Yorkshire were communicated 

 by Mr. Albert Gilligan (Leeds). Following up the 

 work of Dr. Sorby, the late Mr. A. Longbottom had 

 collected some very large pebbles from the Middle 

 Grits of Silsden. These had been examined by the 

 author, who had extended his researches to other 

 beds of the series in Yorkshire. Some of the pebbles 

 were of considerable size and showed a remarkable 

 assemblage of rocks. By far the most common were 

 acid igneous rocks. Only one specimen of a basic 

 igneous rock had been found. The metamorphic 

 rocks were quartz-schist and mica-schist, with a few 

 fragments of gneiss. Numerous pebbles were found 

 to be perfectly fresh microcline. Pieces of pegmatite 

 were common. Some fragments obtained from the 

 Plompton Grit proved to be a peculiar silicified oolitic 

 rock. A few pebbles showed traces of organisms such 

 as sponge spicules. The heavy minerals of the grits 

 were not numerous, zircon and garnet being the most 

 plentiful. The felspars in the grit were quite fresh, 

 and this suggests either disintegration of the parent 

 rock by differences of temperature and rapid trans- 

 portation, or comparative absence of carbonic dioxide 

 in the atmosphere. The author had been much im- 

 pressed by the many points of similaritv between the 

 Millstone Grit and the Torridon Sandstone, and was i 

 disposed to think that areas of similar rock types were 

 laid under contribution for each. | 



Mr. T. O. Rosworth gave an account of some in- i 

 vestigations into the heavy mineral grains in the sands 

 of the Scottish Carboniferous. The chief heavy j 

 minerals found were garnet, zircon, magnetite, tour- j 

 maline, rutile, staurolite, anatase, barvtes. The sands i 

 containing an extraordinary amount of angular garnet j 

 were probably derived from the Highland schists of ' 

 the north and north-west. The sands devoid of garnet 

 probably came from the north-east, east, or south. 



Mr. J. S. Owens communicated the results of some 

 experiments on the settlement and transport of sand 

 in water. It was shown that there is a definite rela- • 

 NO. 2242. VOL. 90] 



tion between the rale of settlement and the tempera- 

 ture of the water. The curves show that velocity of 

 fall varies almost with the water temperature, the 

 rate being always increased by rise of temperature, 

 but that as the diameter of the grains increases the 

 temperature effect becomes less, until for grains more 

 than one-tenth inch in diameter the effect is practically 

 negligible. 



Mr. Edward Greenly contributed a theory of the 

 Menai Strait, in which he accepted Ramsay's view 

 of the Strait as a glacial furrow, but the middle of the 

 Strait cannot be explained in that way. Evidence was 

 adduced to show that this reach was excavated by 

 glacial waters during the recession of the ice at a 

 time when the mutual relations of the ice of the 

 mountain land and of the sea-basin admitted of the 

 accumulation of a temporary lake. Post-glacial erosion 

 and subsequent changes of level have completed the 

 bed of the Strait as it now exists. 



The origin of kopjes and inselberge was dealt with 

 by Dr. J. D. Falconer. It had been suggested that 

 a landscape with inselberge was of desert origin, but 

 the various phenomena could be explained more readily 

 as the result of weathering and erosion during succes- 

 sive small oscillatory movements of a regional char- 

 acter in the neighbourhood of base-level. 



Mr. G. W. Grabham gave notes of an exploration 

 of the country north of Lake .Albert. This area ex- 

 tends west from Rejaf to the watershed and south- 

 wards as far as the lake. It is entirely composed of 

 gneisses, which are for the most part affected by a 

 north-south foliation. The only member of apparently 

 sedimentary origin consists of a band of quartzite 

 which is traceable for some distance. Among the 

 gneisses, a group characterised by graphitic pegmatite 

 was recognised. Some intrusions occur among these 

 gneisses, and form the only intervening link in time 

 between them and the surface deposits. In the country 

 north of Lake Albert extensive deposits belonging to 

 an extinct lake were found. Lake Ismail, as it is 

 proposed to call this lake, stood about 600 ft. above 

 the present river-level, and its site is marked by gravels 

 and beds of clay. Its limits are uncertain, but it did 

 not extend into the area now occupied by Lake .Albert. 

 In later times the crust fractures of the Rift Valley 

 occurred, and the present lake and river system was 

 initiated. In more recent times still the river has 

 again been modified by crustal movements. 



The usual grants were recommended for the con- 

 tinuance of committees of research, and a new com- 

 mittee was formed to investigate the fish beds of Dura 

 Glen. The meeting was attended by a large number 

 of foreign geologists, who took an active interest in 

 the discussions of the section. Among them were 

 Prof. C. Barrois (Lille), Dr. Tschernyschew (St. 

 Petersburg), Prof. .'\. Heim (Zurich), Dr. H. Reusch 

 (Christiania), Prof. J. Welsh (Poitiers), Prof. E. Trietze 

 (Y'ienna), Dr. Pirrson (Yale), Dr. Leith (Wisconsin). 

 Dr. .^mi (Toronto). The annual geological dinner was 

 held at the Royal Hotel on Friday evening (Septem- 

 ber 6). Dr. Peach made a most genial chairman, and 

 delighted the audience by rendering the " Song of the 

 Seraphim," specially written for the Red Lion Club 

 dinner held during the Dundee meeting in 1867, 

 and then suns' by the author. Dr. Henry Woodward, 

 to the tune of " Bonnie Dundee." The menu card 

 was graced by a photographic copy of the picture of 

 Sir Charles Lvell painted in 1870 by Lowes Dicken- 

 son, when Sir Charles was seventy-three years of age. 

 The picture was on view in the loan collection. Dr. 

 Jehu and his assistants arranged three enjoyable ex- 

 cursions for the afternoons, and a whole day to see 

 the wonderful coast sections of Carboniferous puy 

 eruptions near Elie. At the close of the meet- 

 ing two extended field excursions were arranged, one 



