NATURE 



[December 5, 1912 



genus; bv Dr. Hilzheimer {Abh. Senckeuberg Ges., 

 vol. xxxi., p. 85, under the preoccupied name Mega- 

 cephalon, while the E. burcheUi group is kept distinct 

 from E. qiiagga. Mr. Heller (Smithson. Misc. Collect., 

 vo! Ix., No. 8, p. i) also generically separates Gravy's 

 zebra, as Dolichohippus. Mr. Griffini's work was re- 

 viewed in N.WURE of November 28 (p. 358) ; the re- 

 maining publication does not demand further notice. 



.^N interesting research on the sensory perceptions 

 of the fowl tick (Argas persicus) has been carried on 

 in the Quick Laboratory, Cambridge, by Dr. E'. 

 H indie and Mr. G. Merriman, who publish their results 

 in Parasitology, vol. v., No. 3, 1912. The reaction of 

 thc> ticks, in all stages, to light is negative; they are 

 also sensitive to pronounced differences in the intensity 

 of illumination, selecting the darker places to rest in. 

 Occasionally this " negative phototropism " is masked, 

 because the ticks are decidedly attracted to a source 

 of heat. They bring as much as possible of the sur- 

 face of their bodies into contact with surrounding 

 objects. Experiments with vapours showed that the 

 sense of smell is very well developed, and observations 

 on ticks that had suffered amputation of the 

 terminal segments of their front legs proved that the 

 chitinous sac, there situated, and known as " Haller's 

 organ," is olfactory in function. The impressions 

 received through this organ, together with the posi- 

 tive reactions to heat and contact, are believed to be 

 of service to the ticks in enabling them to find appro- 

 priate hosts. 



We have received a report of the Amphipoda of the 

 .Scottish .Antarctic expedition (Trans. Roy. Soc. Edin- 

 burgh, xlviii. {1912), pp. 455-520, two plates), by Prof. 

 Charles Chilton, of Canterbury College, New Zealand. 

 The collection contained fifty-six species from .'\ntarctic 

 or sub-.^ntarctic seas. The great majority of these 

 were alreadv known, but nine new forms are estab- 

 lished. It appears that many species range around 

 the globe in sub-.Antarctic seas, and the author also 

 directs attention to the similarity or identity of some 

 .Arctic and .Antarctic species. What interpretation is 

 10 be put on this " bipolarity "? Prof. Chilton points 

 out that a species which occurs both in the Arctic and 

 the Antarctic is not always entirely absent from the 

 tropics, but exists there in deeper waters. Moreover, 

 the tropical or temperate form is sometimes so much 

 smaller than the polar one th.U it has been reckoned 

 as a separate species. For it must be noted that, for 

 some reasons not altogether understood, many Amphi- 

 pods find their optimum environment near the Arctic 

 and Antarctic regions, not only occurring there in 

 greatest abundance, but attaining a size far larger 

 than that usual for similar or identical species in 

 warmer seas. 



.A USEFUL list of British lichens, published by 

 Messrs. Dulau, at is. net (post free is. id.), has been 

 compiled by the secretary of the Lichen Exchange 

 Club, and contains the names of more than 1200 

 species, belonging to 142 genera. This list will be 

 of service to collectors, but the club intends shortly 

 i'l publish a census catalogue and also ".'\n Easy 

 \rcount of British Lichens," of which the latter will 

 loubtless be of greater utility to general students. 

 NO. 2249, VOL. 90] 



The enterprise of the Liclien Exchange Club is 

 greatly to be commended, as it is likely to lend an 

 impetus to the study of this difficult group of plants 

 among field botanists, and the issue of these handy 

 and inexpensive compilations is well-timed, following 

 as they do the recently completed monograph of the 

 lichens in the British Museum herbarium. 



The synoptic weather maps of the North Atlantic 

 and adjacent continents during the interval of Novem- 

 ber 4-14, shown on the first issue of the meteoro- 

 logical chart for December by the Meteorological 

 Ofiice, are of more than usual interest. During the 

 first few days atmospheric disturbances occupied the 

 region from Greenland to the Azores and Canary 

 Islands, but subsequently the maps show that a re- 

 markable development of high pressure took place, 

 and " a vast anticyclone ruled from the United States 

 across the Atlantic and Europe to the greater part of 

 Siberia," and much fine weather was experienced. 

 The barometric pressure over central Siberia exceeded 

 31J in. on two days, and was down to 28! in. near 

 Iceland. In the week commencing with November 10 

 a more wintry type of weather set in, with a large 

 anticyclone central about. 52° N., 22° W., and depres- 

 sions on the Newfoundland side. 



A USEFUL paper, entitled " Data of Heavy Rainfall 

 over Short Periods in India," has recently appeared in 

 the Memoirs of the Indian Meteorological Department 

 (vol. xxi., part iii.). The information is arranged in 

 chronological order showing (i) daily falls exceeding 

 10 in. in each of the fourteen chief political divisions 

 for the period 1891-1911, and also the amounts re- 

 corded on the preceding and following days, with a 

 supplementary table giving from fragmentary sources 

 records of heavy rainfall prior to 189 1 ; (2) bursts of 

 heavy rain lasting a few hours. No general summary 

 is given of the maximum daily falls, but the figures 

 are astounding; records of 20 in. and upwards are not 

 uncommon, with considerable falls on the previous 

 and following days. At Cherrapunji (.Assam) 4o'8 in., 

 in the LInited Provinces 35 in., and in the Pi>njab 

 32'4 in. are quoted within twenty-four hours. This 

 valuable information has been published to meet de- 

 mands for trustworthy data for use in irrigational and 

 commercial undertakings. 



The American journal Good I.ighti^ig publishes in 

 its October number a well-illustrati-d article, by 

 Messrs. C. L. Law and A. L. Powell, on small store 

 lighting in tliat country, a subject on which the 

 authors read a paper at the Niagara Falls meeting of 

 the Illuminating Engineering Society in September. 

 More than 800 small stores in the less prominent 

 streets of New Yoric and neighbouring cities were 

 investigated, and the authors embody their results in 

 a table showing the maximum, minimum, and average 

 watts per square foot of floor area, based on the use 

 of tungsten filament lamps with glass reflectors. 

 They conclude by recommending a definite number of 

 watts per sqviarc foot for each type of store. Although 

 the internal arrangements of an American store differ 

 considerably from those of an English shop, the re- 

 commendations arc of importance to English illu- 

 minating engineers, and we reproduce them : — Art 



