July 21, 1923] 



NA TURE 



1 1 1 



Research Items. 



Depopulation of Primitive Communities. — Mr. 

 J. H. Hutton," whose monographs on two branches 

 of the Naga Tribes in Assam have been received 

 with much favour by ethnologists, reviews in Man 

 in India (vol. 2, No. 4) the work of the late Dr. 

 Rivers on depopulation in Melanesia, in the light 

 of his experiences in Assam. He notes that, as in 

 the case of the Kava of Melanesia, the influence of 

 missionary societies in Assam, who discourage the 

 use of the mild rice beer, is driving their converts to 

 opium. The appearance of consumption in recent 

 years in the Naga hills may be attributed to the 

 wearing of European clothes, which is also responsible 

 for the spread of dysentery, itch, and yaws. The 

 absolute prohibition of head-hunting has led to 

 serious interference with all sorts of dependent 

 activities, and ultimately leads to a total lack of 

 interest in life, and so to the limitation of families, 

 or even to the total refusal to procreate children. 

 These facts, which corroborate the conclusions of 

 ]\lr. Henry Balfour in the presidential address recently 

 delivered before the Folklore Society, deserve the 

 serious attention of all those who are responsible 

 for the welfare of primitive societies. 



Bronze Age Weapons in the Hull Museum. — 

 In The Naturalist, No. 795, for April, Mr. T. Sheppard 

 reports further valuable additions to the collections 

 in the Hull Museum. Some of these pieces formed 

 part of the Scarborough hoard, of which twenty-three 

 are now in the museum. The new examples include 

 some interesting axes and palstaves. An analysis 

 of one of the axes by Prof. Cecil H. Desch shows that 

 it contains 80-25 per cent, of copper, 16-39 per cent, 

 of tin, and minute quantities of lead, nickel, and 

 sulphur. 



Contraction and Dilatation of Blood-Vessel. — 

 Special interest has been aroused by the work of the 

 Petrograd physiologist Kravkoff, who is already 

 known for his work on the contraction and dilatation 

 of the blood-vessels of surviving organs. Kravkoff 

 usually employs rabbits' ears, which retain their 

 vitality for a long time. Even after keeping these 

 organs for several days and weeks he obtained a 

 definite reaction with adrenalin. In his investigation 

 he devised two methods for preserving the ears. As 

 the ears usually perish from infection contracted at 

 the cut surface, he seals that end by dipping the 

 excised ears into a vessel with molten paraffin. 

 When the paraffin solidifies the ears stand up in 

 the vessel like plants in a flower-pot, and in this way 

 the vital properties of the vessels are preserved for 

 a long time. The second method is that of drying. 

 The ears are dried in an evacuated desiccator over 

 sulphuric acid until the moisture content is 5-6 per 

 cent. Such preparations can be kept for about three 

 months, and after soaking they respond to chemical 

 stimuli. In this way also organs of higher animals 

 show parabiosis after drying. It was also found 

 convenient to employ human fingers, from amputations 

 or later from corpses, for the study of the blood- 

 \essels. These organs are just as sensitive in re- 

 sponding to poisons and adrenalin and can be utilised 

 as anatomical specimens as well. They can also be 

 preserved and dried. These surviving organs also 

 possess the property characteristic of living animals, 

 that their skin reacts to cantharadine, producing a 

 focus of local inflammation with a blood-vessel 

 reaction and tissue cedema. 



The Allantoic Placenta of Marsupials. — One 

 of the results of the visit of the British Association 

 for the Advancement of Science to Australia in 1914 



was the establishment of a committee to promote 

 the collection of material for the study of the mar- 

 supials, with special reference to their embryology, 

 a task rendered imperative by the rapid extermina- 

 tion of the native fauna. The principal part of the 

 work of this committee was entrusted to Prof. T. 

 Thomson Flynn of the University of Tasmania, who 

 gives us the first instalment of his embryological 

 results in a memoir on the Yolk-Sac and Allantoic 

 Placenta in Perameles, published in the current 

 number of the Quarterly Journal of Microscopical 

 Science (vol. 67, part i). It was in Perameles that 

 Prof. J. P. Hill first discovered the existence of an 

 allantoic placenta in the supposedly " non-placental " 

 marsupials. Prof. Flynn confirms and extends 

 Hill's observations, and endeavours, apparently with 

 success, to reconcile the supposed discrepancy between 

 the development of the marsupial allanto-placenta 

 and that of the primitive eutherian type, maintaining 

 that the difference between the two is one of degree 

 rather than of kind. He draws a close comparison 

 between the early stage of the allanto-placenta in 

 Perameles and that of the dog, and holds that both 

 can be derived from a common ancestral condition. 

 He agrees with Hill in attributing the absence of an 

 allantoic placenta in the majority of the Marsupialia 

 to degeneration. 



The Pleistocene of North America and its 

 Vertebrates. — The Carnegie Institution of Washing- 

 ton has issued as its Publication No. 322 a substantial 

 volume by Mr. O. P. Hay on " The Pleistocene of 

 North America and its Vertebrated Animals from 

 the States east of the Mississippi River and from the 

 Canadian Provinces east of longitude 95°." By the 

 author, who is obviously a thoroughgoing glacialist, 

 " the Pleistocene is regarded as being equivalent to 

 what is known as the Glacial Period," and is divided 

 by him into nine stages, five glacial and four inter- 

 glacial, while the Blanco is held to belong to the 

 upper, or uppermost. Pliocene. His Pleistocene is, 

 therefore, obviously not quite homologous with the 

 period that passes under that name with British 

 geologists. The various vertebrates are first dealt 

 with mostly in groups, cetaceans, mastodons, etc., 

 but sometimes by individuals, as in the case of three 

 species of Elephas ; and their occurrences in each 

 State, county by county, is recorded and charted on 

 maps. To this succeeds a section on the Pleistocene 

 geology of the several States, with the assemblages 

 of animals found in the various beds. Whether the 

 value of all this painstaking work will prove com- 

 mensurate with its bulk of 500 octavo pages, time 

 alone can show. The author's conclusions as to the 

 dates of advent and disappearance of the different 

 forms that are summed up in the table on pp. 14-15 

 depend obviously on the correctness or otherwise of 

 the determination of the age of the individual deposits 

 in which their remains occur, a matter concerning 

 which the author himself appears frequently to be 

 doubtful, and on whether all the fossil contents of a 

 given bed truly belong thereto, as the author seems 

 always to assume, or may in some cases be mixed 

 with others derived from older horizons. In any 

 case this memoir will prove most useful to all interested 

 in the subject, whether from the geological or palae- 

 ontological point of view. 



Virus Diseases of Plants. — The brief report in 

 Phytopathology, vol. 13, No. 4, of the symposium 

 upon mosaic diseases by the Physiological Section of 

 the Botanical Society of America ancl the American 

 Phytopathological Society records proceedings which 



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