September 9, 19 15] 



NATURE 



49 



Two important papers appear in the American 

 aturalist for August. The first of these should be 

 irefully read by all who are interested in problems 

 ! heredity. Herein Mr. E. M. East discusses at some 

 iigth "The Chromosome View of Heredity and its 

 Moaning to Plant-Breeders." He contends that the 

 naximum possible difficulty in the improvement of 

 animals, and plants, by hybridisation, usually depends 

 directly upon the chromosome number. This being 

 .1, then there can be no question as to the import- 

 ice of determining the number of chromosomes in a 

 i)L'cies before beginning a complex plant-breeding 

 j)i-oblem, and thus being able to comprehend the maxi- 

 mum possible difficulties that may be encountered. 

 In the second paper Prof. A. C. Eycleshymer dis- 

 cusses the origin of bilaterality in vertebrates. From 

 tudy of the early embryonic stages he is of opinion 

 t neither the position nor the direction of cleavage 

 coves has the slightest significance as far as the 

 setting apart of definite embryonic areas is concerned. 

 And further, that neither the position nor the direc- 

 tion of the cleavage grooves enables one to predict the 

 long axis of tjie embryo, so that other phenomena, 

 which may be of service, must be looked for. These 

 he finds in the increased cellular activity of the active 

 pole, which can be located with the advent of the 

 first cleavage groove. This marks the head end of the 

 embryo. The tail end is similarly marked by the early 

 accelerated activity of the side of the egg, indicating 

 the forthcoming blastopore, which definitely fixes the 

 posterior end of the embryo. It necessarily follows 

 that the median plane of the embryo must coincide 

 with a line passing through the centres of the two. 



There is much that may be profitably ruminated on 

 in the Museums Journal for August, even by those 

 who have no part in the conduct of museums. More 

 especially we refer to the views expressed at the con- 

 ference of the Museums Association held in London 

 during July, as to the relation which should exist 

 between museums and the various grades of educational 

 institutions. In Manchester, where so many of the 

 school buildings have been converted into military 

 hospitals, a number of teachers have been sent to the 

 museums to receive a thorough course of instruction 

 on the various aspects of the museums to which they 

 are sent, in order that, when peace returns to us, 

 they may the more efficiently utilise the museums as 

 sources of education. Many valuable suggestions for 

 the further widening of the spheres of usefulness of 

 museums were also made, some of which, at any rate, 

 might well receive immediate attention. The address 

 of the president, Mr. E. Rimbault Dibdin, might be 

 read with much profit by the peace cranks who just 

 now are so busy. 



Mr. G. B. Walsh makes some interesting observa- 

 tions on the causes determining the survival and ex- 

 termination of insects in the manufacturing districts 

 of Yorkshire in the Entomologist's Monthly Maga- 

 zine for August. Drainage, cultivation, and moorland 

 fires have done much, but blast-furnaces and chemical 

 works have done more, to bring about the extinction 

 of many insects that were once common in. the areas 

 surveyed. Some have contrived to thrive under the 

 NO. 2393, VOL. 96] 



most adverse conditions. Thus he relates how two 

 very local beetles, moorland species — Miscodera arctica 

 and Pterostichous vitreus — are to be found, in some 

 numbers, in a marsh traversed by a foetid stream, and 

 stinking most abominably of hydrogen sulphide. A 

 slag heap bounds the marsh on either side, which 

 receives the overflow from a neighbourhing chemical 

 works, while dust from calcining and blast-furnaces 

 fills the air, which is saturated with the odour of 

 rotten eggs. How insects the natural home of which 

 is the breezy moorland can contrive to thrive under 

 such appalling conditions is indeed a mystery. Speci- 

 mens taken from this new habitat should be carefully 

 compared with others obtained from the moorland to 

 discover, if possible, whether any adaptations to the 

 new environment have taken place. 



The accurate zoning of Carboniferous strata in the 

 British Isles has received general attention since the 

 pioneer work of A. Vaughan on the Avon section. 

 L. B. Smyth, lecturer on palaeontology in the Uni- 

 versity of Dublin, has now (Sci. Proc. R. Dublin 

 Society, vol. xiv., 1915, p. 535) cleared up some 

 obscure points in the sequence in the north of the 

 county of Dublin, where a river from the Devonian 

 land-surface entered the Carboniferous sea. A corre- 

 lation is made between these Irish deposits and those 

 of the English Lake District, described by E. J. 

 Garwood. Several new species of corals, and a new 

 genus, Arachniophylium, are described. The old 

 Arachnophyllum, by the by, has been absorbed in 

 Strombodes; but it might have been well to direct 

 attention to this, the new generic name being almost 

 identical. 



From a new consideration of the " Interglacial 

 Gorges of Six Mile Creek at Ithaca, New York" 

 (Journ. of Geology, vol. xxiii., 1915, p. 59), J. L. 

 Rich and E. A. Filmer conclude that at least three 

 glacial epochs are indicated, "separated by periods of 

 time longer than that since the last epoch." The 

 great Wisconsin ice-extension entered the inter- 

 glacial stream-gorges, and deposited its drift there, 

 without appreciably modifying their walls. 



F. Chapman describes a new genus of dibranchiate 

 cephalopods, Notosepia, from the Oligocene of 

 Victoria, Australia (Proc. R. Soc. Victoria, vol. 

 xxvii., 1915, p. 357)- Young forms have a recurved 

 mucro at the termination of the pro-ostracum, recall- 

 ing the Eocene Belosepia, while this becomes, in 

 adult specimens, straightened towards the type known 

 in the modern Sepia. 



Students of meteorites will be glad to note the 

 record of the rare calcium sulphide, Oldhamite, which 

 crystallises in the cubic system, in the "carbonaceous 

 chondrite" of Indarch, Russia (G. P. Meirill, Proc. 

 U.S. Nat. Museum, vol. xlix,, 1915, p. 109). Mr. 

 Merrill quotes its occurrence in five other meteorites 

 of varied composition, and points out that it may 

 prove to be more widely diffused, since it is usually 

 inconspicuous. 



The use of antiseptics or disinfectants for the treat- 

 ment of wounds is limited by several factors. Thus 

 many potent germicides rr.Jy bs irritating to the tissues 



