November 



[917] 



NATURE 



17; 



nents are described, most of them being referable to 

 he well-known generalised group of the Palaeodictyo- 

 ptera. 



The sixth volume of the " Icones Plantarum Formo- 

 sanarum," by Bunzo Hayata, has recently been pub- 

 lished, and, like its predecessors, is a valuable con- 

 tribution to our knowledge of the flora of the island. 

 There are 168 pages of text, containing studies of 212 

 s[>ecies, belonging to a large number of natural fami- 

 lies, 126 of which are new to science. One genus, 

 Parasitipomaea, is described for the first time, and 

 there are nine genera recorded which hitherto have 

 been unknown in Formosa. The new genus, belonging 

 to the Convolvulaceag, is interesting in having flowers 

 like those of Ipomaea, but the plant is a leafless para- 

 site. A large number of new orchids, sedges, and 

 grasses are among the plants described and figured. 

 Throughout the text there are numerous excellent 

 figures, and the volume is further enriched by twenty 

 well-drawn plates. 



The recently received report of the Ceylon Agricul- 

 tural Department for 1916 gives indication of activity 

 and sound work under the new director, Mr. F. A. 

 Stockdale. A welcome sign of the new administration 

 is the issue of practical leaflets, intended for the use 

 of planters, on plant and insect pests and other agri- 

 cultural matters. Three of these have recently been 

 published. No. 3 deals with the beautiful fluted scale 

 which attacks Acacia trees, and in California is a 

 serious pest on Citrus. In Australia, whence the pest 

 seems to have come, it is held in check by parasitic 

 flies, etc. The leaflet is issued as a warning to prevent, 

 if possible, the spread of the insect. The second leaflet 

 is concerned with the black-rot disease of tea, a sterile 

 fungus of the genus Hypochnus, which attacks the 

 leaves, and may prove to be a serious menace to the 

 tea industry of the island unless kept under control. 



An account of observations made during the past 

 three or four years on the cause of the common dry- 

 rot of the potato tuber in the British Isles is com- 

 municated by Dr. G. H. Pethybridge and Mr. H. A. 

 Lafferty to the Scientific Proceedings of the Royal 

 Dublin Society (vol. xv. (N.S.), No. 21, June, 1917). 

 In confirmation of previous work, it is established that 

 the dry-rot of the potato tuber which commonly occurs 

 in the British Isles is due to the attacks of a parasitic 

 species of Fusarium, which is now definitely identified, 

 however, as F. coeruleum (Lib.), Sacc, rather than 

 '■: F. Solani, Sacc, as was previously believed. F. 

 coeruleum does not produce hadromycosis of the potato 

 plant, nor does it kill the plant by attacking the roots. 

 It can destroy tomato fruits, but does not sttack 

 onions, mangels, carrots, parsnips, or apples. Infec- 

 tion takes place through wounds, but can also be 

 effected through the lenticels, eyes, or young sprouts 

 of uninjured tubers. Some varieties of potatoes are 

 more resistant to infection than others. Potatoes be- 

 come more susceptible to infection as they become 

 more mature, hence the rot is more prevalent during 

 the later than during the earlier period of storage. 

 No effective preventive measure or cure has yet been 

 devised. 



in which year Lipoid published a geological map of 

 the Isonzo valley. At Idria are mmes of cinnabar, 

 discovered in 1490. More recently a new tunnel on 

 the line to Tolmino has been the subject of a paper 

 by Franz Kossma. The works of Bruckner and 

 Penck on this district are discussed in considerable 

 detail, and the paper is illustrated by a map showing 

 the "course of the principal rivers and the peri-Adriatic 

 fracture. 



The " Report on the Building and Ornamental Stones 

 of Canada," vol. iv. (Manitoba, Saskatchewan, and 

 Alberta), issued by the Canadian Department of Mines, 

 contains characteristic and excellent coloured plates 

 showing the texture ot the principal rocks described. 

 The modes of testing are stated, among them being 

 a corrosion test, in which cubes of stone are suspended 

 for four weeks in a vessel containing water into which 

 carbonic acid gas and oxygen pass. The loss or gain 

 in weight is calculated to the square inch of exposed 

 surface, and in no case is a gain in weight recorded. 

 .Arrangements are made for securing that the pressure 

 in the liquid remains uniform, since this factor largely 

 affects the solution of limestone. It is important to 

 note colour-changes resulting from this test ; thus 

 bluish sedimentary rocks may become distinctly yellow. 

 The porosity test is conducted by filling the pores with 

 water under a pressure of 2000 lb. to the square inch, 

 continued for twenty-four hours. The limestones vary 

 in pore-space froTn 0292 up to 12-72 per cent., while 

 one of the granites, which shows considerable fractur- 

 ing in the field, has a porosity as high as 0606. 



A REPORT of the Liverpool Observatory at Bidston by 

 the director, W. E. Plummer, published by the Mersey 

 Docks and Harbour Board, gives detailed seismologica) 

 and meteorological observations for the year 1916. In 

 the course of the year 184 earthquakes were registered, 

 and a table is given showing the time and amplitude 

 of each. Tables are given of the total amount of sun- 

 shine and the maximum wind velocity recorded on a 

 Dines anemometer for each day, and there are daily 

 results of the barometer, temperature, rain amount and 

 duration, velocity and pressure of wind, with the points 

 of the compass from which the wind blew\ The old 

 units of measurement are still adhered to, although 

 in the summary of results for the year the barometric 

 measurements and the rainfall are given in inches and 

 millimetres, and the air temperature in Fahrenheit and 

 Centigrade. Thermometers are exposed in Steven- 

 son's screens, both on the north and south sides 

 of the observatory, and the comparison is said to 

 show that the past records, made entirely on the 

 south side, are too high, owing to radiation from the 

 southern front. No failure occurred throughout the 

 year in the firing of the gun as a time-signal for the 

 shipping in the neighbourhood. 



Symons's Meteorological Magazine for October shows 

 the weather conditions for September to have varied 

 considerably in different parts of the British Islands. 

 The rainfall tables afford a fairly good representation, 

 for so early a date, of the relaitive dryness of Septem- 

 ber in most parts of the country, although there was 

 an excess of rain in places. In' the English midlands 

 the rainfall was mo&tly slight, and at Worksop, Nott- 

 inghamshire, the total measurement was only 31 per 

 cent, of the aveiage. At Borrowdale, Cumberland, the 

 rainfall was 1S04 in., which is 676 in. more than the / 

 average. In parts of Cumberland and Westmorland 

 the September rains are said to be as much as 20-25 in. 

 in places. For England and Wales the rainfall for 

 the month is given as 88 per cent, of the average, 

 Scotland 95 per cent., and Ireland 77 per cent. 'Hie 

 mean temperature was above the average in most 

 parts of the United Kingdom, and there was generally 



