June 26, 1914] 



SCIENCE 



945 



counts for both the origin and purpose of sec- 

 ondary sexual characters in the following way. 

 Males are more conspicuous in nature than 

 females : males are less valuable than females. 

 Males and females are associated together 

 during life, and especially during the breeding 

 season when the difference in color is greatest, 

 and when their difference in value is highest; 

 therefore according to the theory, the con- 

 spicuous color of the male serves to control 

 natural selection in such a way that the less 

 valuable male will be killed in preference to 

 the more valuable female." 



It is assumed that if the male is taken, the 

 female and young will not be taken. But the 

 reader might reasonably inquire how the fam- 

 ily would be benefited by the loss of its 

 strongest member, and how the survivors would 

 be protected after his demise. Is it to be sup- 

 posed that the appetites of all enemies will be 

 permanently appeased by a single meal, and 

 that the father having been taken the family 

 will not be further molested? 



Not only conspicuousness due to color but 

 also such as may arise from movement, sound 

 or scent is interpreted in this same way. This 

 puts a new meaning on courtship and other 

 means of display and on song, which are all 

 supposed to be protective to the family in 

 which they occur by causing the destruction 

 of those individuals which thus advertise 

 themselves, which result is then supposed to 

 give the others a better chance to survive. 



For illustrations in support of his theory 

 the author relies chiefly upon British birds, 

 though reference is frequently made also to 

 insects. 



W. E. Castle 



PUBLICATION OF TME AMEBIC AN EPHE- 



MEEIS AND NAUTICAL ALMANAC 



FOB 1916 



Tpte American Ephemeris and Nautical 

 Almanac for the year 1916, recently issued by 

 the U. S. Naval Observatory, differs materially 

 in construction and arrangement from previ- 

 ous numbers of this publication. 



The preparation of this volume marks the 

 inauguration of the scheme of cooperation 



adopted by the congress of representatives of 

 the various national Ephemerides held at Paris 

 in 1911. In accordance with this agreement a 

 portion of the material contained in the vol- 

 ume for 1916, including the greater part of 

 the Greenwich Ephemerides of the moon and 

 planets and the apparent places of the stars, 

 has been supplied by the foreign almanac 

 offices, while the office of the American Ephe- 

 meris has in turn furnished to all foreign 

 offices the data regarding eclipses, occultations, 

 physical ephemerides of the sun, moon and 

 planets, etc. This system of exchange re- 

 duces considerably the amount of duplication 

 of work by different computers, and will, it is 

 believed, prove mutually beneficial to the 

 offices concerned. 



Congress has, however, in the law authoriz- 

 ing this exchange, provided that any such ar- 

 rangement shall be terminable on one year's 

 notice and that the work of the Nautical 

 Almanac Office during the continuance of any 

 such arrangement shall be conducted so that 

 in ease of emergency the entire portion of the 

 work intended for the use of navigators may 

 be computed by the force employed by that 

 office, and without any foreign cooperation 

 whatsoever; and that employees whose services 

 in part can be spared on this account may be 

 employed in improving the tables of the plan- 

 ets, moon and stars, to be used in preparing 

 for publication the annual volumes. 



A rearrangement of the material contained 

 in the first part of the Ephemeris has been 

 made, with the view of giving it in better and 

 more convenient form for the astronomer. 

 Instead of giving portions of the ephemerides 

 of the sun and moon alternately, month by 

 month, there is now given for the entire year 

 first the ephemeris of the sun complete, then 

 the ephemeris of the moon complete, then the 

 ephemeris of each of the seven major planets. 



Other changes worthy of note are the fol- 

 lowing: Daily ephemerides are given for 35 

 circumpolar stars instead of 25, and they have 

 been arranged in more convenient form. The 

 apparent right ascensions of stars whose 

 declination is less than 60° are given to 0.^001, 

 and the apparent declinations of all stars are 



