24 



NATURE 



[March 3, 192 1 



ment, settlement, and spurt — and in most factories 

 probably of more. Examples from some of the publica- 

 tions of the Industrial Fatigue Research Board show 

 the disadvantages of the ten-hour as against the 

 eight-hour working day, and also the improvement 

 resulting from suitably arranged rest-pauses. The 

 author points out, however, that a certain amount of 

 fatigue is not only inevitable, but also beneficial ; it 

 is when the fatigue cannot be dissipated by rest that 

 the condition is serious and the work suffers. The 

 difference between the work of a machine and that of 

 a human being is emphasised; it is unnatural for the 

 latter to maintain a uniform output hour by hour. It 

 is also necessary for industry to recognise the im- 

 portance of individual differences among workers. 

 Dr. Myers concludes by referring to the work of the 

 Industrial Fatigue Research Board and of the 

 National Institute of Industrial Psychology, which 

 latter continues and develops the more general work 

 of the Board for special firms. Although these bodies 

 have been working but a short time, their researches 

 have clearly shown the very complex nature of indus- 

 trial fatigue problems and the urgent necessity for 

 scientific investigation by impartial workers. 



Sixty-one pages on the growth of the antenna in 

 termites might be thought disproportionate, but Mr. 

 C. Fuller has made a really interesting study (Annals 

 of the Natal Museum, vol. iv., p. 235, November, 

 1920). The number of segments in the antenna has, 

 as in other insects, been held to distinguish various 

 species, and even the length of the basal segment, 

 numbered III., has been taken as diagnostic. But 

 when soldiers of one species from a single colony 

 were found with antennae ranging from seventeen to 



nineteen segments, this practice clearly called for re- 

 consideration. It now appears that the segments are 

 produced by separation from this segment III., and 

 normally two at a time. The two segments of a pair 

 may fuse or the proximal element may not be 

 separated from III., and in this way arise antennae 

 with an odd number of segments. The relative length 

 of III. depends on the number of segments that have 

 been separated from it. The variation of number is 

 governed by a general tendency to reduction through- 

 out the group and by various environmental factors, 

 of which nutrition is the most important. All 

 antennae, even in the adults of the most fully 

 developed species, show within segment III. un- 

 separated segments, and are therefore arrested 

 organs. This gradual and continuous response to 

 the environment in a segmented organ has an 

 obvious bearing on theories of evolution, and Mr. 

 Fuller's paper deserves study by general biologists. 

 Fortunately, it is v^ell arranged and well written. 

 But we do not like the words "quiescency" and 

 " monolocular " ; we do not understand how " acro- 

 genous " can apply to growth in a proximal region ; 

 and we protest against the use of the anatomical 

 term "joint" when "segment" is intended. 



Messrs. Newton and Co., Ltd., 37 King Street, 

 Covent Garden, W.C. 2, have recently prepared a set of 

 lantern-slides for a lecture on "Wireless Telegraphy" 

 dealing more particularly with the Elwell-Poulsen 

 system. The slides, many of which are from hitherto 

 unpublished photographs, are accompanied by a full 

 set of notes, which provides alternative methods of 

 treatment for audiences of varying degrees of ac- 

 quaintance with the subject. 



Our Astronomical Column. 



The Date of Easter. — A Bill to fix the date of 

 Easter as the second Sunday in April has been intro- 

 duced into the House of Lords by Lord Desborough. 

 This Bill may serve to focus attention on the matter, 

 but it is scarcely likely of itself to do more, for the 

 question is one that calls for international and 

 ecclesiastical co-operation, as was recognised by the 

 Astronomical Union when it appointed Cardinal 

 Mercier to preside over the Commission on Calendar 

 Reform. Isolated action would only increase the 

 present inconvenience, and obviously a Parliamentary 

 decision would not be accepted by a considerable sec- 

 tion of the community in such a matter as the altera- 

 tion of the date of a religious festival. 



Ancient Star Maps. — Dr. M. Schonfeld contributes 

 an article to La Nature for February 5 on pre- 

 historic astronomy in Scandinavia. He reproduces 

 some old rock sketches found at Bohuslan, Venslev, 

 and Dalby. They appear unmistakably to be in- 

 tended to represent several notable star groups, Ursa 

 Major being repeated three or four times, while 

 Bootes, Virgo, and Cassiopeia are also more or less 

 roughly delineated. It would appear that these 

 designs are not very many thousands of years old, as 

 several sketches of men and animals accompanying 

 the star groups indicate that the constellations were 

 already mapped out substantially as we now know 

 them. The Bull, Archer, Great and Little Dog, and 

 the ship Argo can all be traced. Moreover, Arcturus 



NO. 2679, VOL. 107] 



moves through o-6° in 1000 years, and while the sketch 

 of Bootes is too rough to assign a date to it with any 

 accuracy, we can at least say that it Jis unlikely to 

 have been drawn more than 10,000 years ago. Dr. 

 Schonfeld claims that different sketches represent the 

 sky at different seasons of the year, but he seems to 

 overlook the fact that unless we know the approxi- 

 mate date of the drawings we may be several months 

 in error through the effects of precession. 



The 1920 Opposition of Mars. — Popular Astro, 

 notny for February contains very interesting drawings 

 and photographs of Mars made at Flagstaff Observa- 

 tory last spring, together with articles by E. C. 

 Slipher and G. H. Hamilton. The aspect of Syrtis 

 Major was very unusual, considerable sections of it 

 being covered by a white veil, apparently cloud or 

 mist. It was noted that this white region was not 

 surrounded by a dark band, as was the polar cap; and 

 it is concluded that the latter band is not illusory, as 

 some have contended. Mr. Hamilton notes that the 

 Syrtis appeared normal until March 8, and was then 

 modified in two different ways. Besides the partial 

 covering by white cloud, the south-eastern edge of the 

 Syrtis appeared to fade and merge into the adjacent 

 desert. Both Mr. Hamilton and Mr. Slipher refer to 

 the veiling by mist near the limb which is a familiar 

 feature, but at the recent opposition the mist seems 

 to have persisted an unusually long time after 



