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NA TURE 



[June 3, 1922 



Research Items. 



Knots in Ancient Egypt. — Miss M. A. Murray 

 contributes to Ancient Egypt (Part I., 1922) an 

 interesting article on the representations of various 

 kinds of knots on early Egyptian monuments. It is 

 a remarkable fact that in the early dynasties knots 

 were never represented, but in the Middle Empire, 

 though the same prejudice still existed, there was a 

 movement towards an accurate presentation of the 

 knot, showing that there was a change, and that the 

 old ideas were beginning to pass away. Miss Murray 

 does not propose an explanation of this curious 

 taboo of the knot on the ancient monuments. It 

 may be suggested that it was based upon the use of 

 knots in magic. Among many races, knots, real or 

 symbolical, are used as a magical means of obstruct- 

 ing some special action. Thus the use of knots at 

 marriage is often disapproved. However this may 

 be, the paper, with good illustrations of various 

 forms of knots and their uses, is of considerable 

 interest. 



The Piltdown Skull. — An important contribution 

 to the controversy over the Piltdown Skull was made 

 by Profs. Elliot Smith and Hunter at a meeting 

 of the Anatomical Society held on May 12, when they 

 exhibited a reconstruction of the skull and its 

 endocranial cast. The reconstruction has been made 

 by a careful and minute examination and correlation 

 of the anatomical points of the fragments of the skull. 

 The result confirms generally the reconstructions 

 made by Dr. Smith Woodward and Mr. Pycraft 

 when first the skull was discovered, and agrees in 

 showing the remarkable breadth of the skull and its 

 low capacity, which is, in each case, placed below 

 1300 c.c. This later reconstruction, however, differs 

 in one important particular. The occipital fragment 

 assujnes a more vertical position, with the effect that 

 the skull is brought into closer relation with the skull 

 of the anthropoids. As a result, the cranium falls 

 into complete harmony with the chimpanzee-like 

 jaw, and the paradox which has hitherto been a 

 stumbling-block to the acceptance of the jaw as 

 indubitably belonging to the fragments of the cranium 

 now disappears. 



Sand- and Mud-binding Plants. — An interesting 

 exhibit is made in Museum IV., at Kew, of plants 

 used for binding sand and mud. Erosion of bare 

 sand dunes and mud flats by wind and tide is so 

 serious in some coastal regions that the services of 

 engineers and forest officers are constantly engaged 

 upon protective work. Violent winds disturb large 

 quantities of sand, the contour of dunes is constantly 

 changing, and sand encroaches upon cultivated land 

 or is piled in positions that interfere with the domestic 

 and business life of the people. Bare mud flats 

 also undergo constant change by tidal action, and 

 adjacent agricultural land is imperilled. Protective 

 work takes the form of barriers to check scour, and 

 the insertion of such plants as are capable of binding 

 sand or mud. After sand dunes have been fixed 

 by low, dense grasses, other plants soon appear, 

 and the forester assists by planting pine trees, thereby 

 changing desert areas into pleasant places of residence. 

 Mud flats that become overgrown with coarse grasses 

 collect debris and, rising gradually above high- 

 water mark, are turned into rich pasturage. The 

 most satisfactory sand binder is " Marram Grass " 

 {Ammophila arundinacea) (Kew Bulletin, No. 9, 1913, 

 PP- 363-366. "Marram Grass for Paper-making"), 



and the best grasses for binding mud flats are species 

 of Spartina. Articles on Spartina in connection 

 with coast erosion appeared in the same journal 

 (No. 5, 1907, pp. 190-197, and No. i, 1918, pp. 26-31). 



Additions to the Insect Fauna of Britain. — 

 Recent issues of the Entomologist's Monthly Magazine 

 contain records of several interesting and, in some 

 cases, important additions to the insect fauna of 

 Britain. In the March number, Mr. K. G. Blair 

 mentions the occurrence of the beetle Carpophilus 

 ligneus, Murray, in several widely separated localities, 

 ranging from the Isle of Wight northwards to Liver- 

 pool. In each case it was discovered associated with 

 merchandise. The species was originally described 

 from Mexico, and has also occurred in Central America, 

 but does not appear to have been noticed hitherto 

 in Europe as a possible pest of commerce, although 

 its congener, C. hemipterus, L., is an almost cosmo- 

 politan species affecting dried fruits and other 

 provisions. In the April issue, Mr. H. St. J. Donis- 

 thorpe records the beetle Nebria iherica, Oliv., which 

 appears to have been confused hitherto with the very 

 common N. hrevicollis. Dr. G. Enderlein publishes 

 in the May number of that same journal the 

 description of a new genus and species of scaly-winged 

 Psocids, specimens of which came from Crowborough, 

 Sussex (F. J. H. Jenkinson). The insect, which he 

 designates as Pteroxanium squamosum, belongs to a 

 sub-family previously known only from New Guinea 

 and Ceylon ; the occurrence of a representative in 

 Europe is therefore very remarkable and suggests 

 the possibility that it is not indigenous but has been 

 imported by some means or other. In the same 

 issue Mr. F. W. Edwards describes a new genus and 

 species of gall midge from North Sussex, the early 

 stages of which are passed among bark-encrusting 

 fungi, upon which blister-like swellings are caused. 

 It appears to be the first record of an Cecidomyiid 

 fly producing a fungus gall. Prof. F. V. Theobald, 

 in Bulletin of Entomological Research, Feb. 1922, 

 describes a new genus and species of aphid, Laingia 

 psammcB, from marram grass and meadow foxtail in 

 Kent. It was preyed upon by numerous ladybirds, 

 particularly the common two-spotted species. 



Increasing the Sensitiveness of Photographic 

 Plates. — M. Clerc, in his " Paris Notes " in the 

 British Journal of Photography, May 19, refers to 

 M. F. Monpillard's success in 1912 in increasing the 

 sensitiveness of autochrome plates about 30 times. 

 The process was also applicable to ordinary plates, 

 increasing their colour sensitiveness as well as their 

 ordinary sensitiveness. The defect of the method 

 was that the treated plates would not keep in usable 

 condition for more than a day at the very longest. 

 Hoping to overcome this difiiculty M. Monpillard 

 did not publish the details of his method, but deposited 

 a sealed packet with the French Photographic 

 Society. As he is unable to continue the work, he 

 has now desired the Society to open the packet and 

 disclose the information given therein. The process 

 consisted in adding a small quantity of silver chloride 

 dissolved in dilute ammonia to the mixture of the 

 usual isocyanine and carbocyanine dyes (pinaverdol, 

 pinacyanol, etc.). As soon as the sensitising bath 

 has been used, the liquid that adheres to the plate 

 must be quickly removed with a whirler, and the 

 plate then dried by a rapid current of air. 



NO. 2744, VOL. 109] 



