434 



NATURE 



[August i, 191 8 



have been observed to give measurable displacements 

 confirm the earlier results, and seem to place beyond 

 reasonable doubt the conclusion that the sun behaves 

 approximately as a uniformly magnetised sphere,_with 

 a polarity corresponding with that of the earth. The 

 deduced values of the field-strength in Gaussian units 

 at the sun's magnetic pole range from 99 to 54-7, 

 but it is shown that, in general, the values corre- 

 sponding with a given line-intensity are approximately 

 equal. For iron and chromium, at least, there is a 

 rapid decrease in field-strength with increasing line- 

 intensity, and, in view of Mr. St. John's conclusion 

 that lines of increasing intensity represent successively 

 higher levels in the solar atmosphere, it would appear 

 that the strength of the sun's general field falls off 

 rapidly with increasing elevation above the surface. 

 The part of the field at present accessible to observa- 

 tion lies within the bounding surfaces of a thin shell 

 in the solar atmosphere about 150 km. in thickness. 

 The anomalous behaviour of certain lines which fail 

 to show displacements has not yet been completely 

 explained, but the lines in question may possibly 

 originate outside the effective field. 



The Spectroscopic Binary Boss 1082. — This 

 star, of magnitude 5-3 and type G5, was found to 

 have a variable velocity by the observers at Mount 

 Wilson. The orbit has now been computed by Mr. 

 J. B. Cannon from forty-two photographs of the 

 spectrum taken at the Dominion Observatory, Ottawa, 

 during the vears iqi6, 1917, and 1918 (Journ. R.A.S. 

 Canada, vol. xii., p. 210). The elements of the orbit, 

 v^'ith their probable errors, are as follows : — 



P= 121 days 



K = 28- 1 9 km. ±1-2 km. 



(f=o'oi9 ±0-042 



a. =285° ±42-68= 



y= -40'47 km.±o-8i km. 



T = J.D. 2,42i,i37-55± 14-26 days 



a sin 2=46,900,000 km. 



{myVvif 



= 0-28 xsun 



MARINE BIOLOGY IN THE UNITED 

 STATES. 



UNDER the direction of Dr. A. G. Mayer, the 

 Department of Marine Biology of the Carnegie 

 Institution of Washington continues to carry out re- 

 searches of great value, and vol. xii. of the Papers 

 from the department, issued 'March, 1918, fully main- 

 tains the high standard of previous volumes. From 

 the point of view of general interest, perhaps the most 

 striking paper is Mr. E. W. Gudger's account of the 

 habits of the gaff-topsail catfish {Felichthys felis), a 

 large catfish which is found at Beaufort, North Caro- 

 lina. In this species the ova, which are very large, 

 being as much as i in. in diameter, are carried in 

 the mouth of the male parent until the larvae are 

 hatched, and the young are retained in this situation 

 for some considerable time until the yolk-sac has been 

 absorbed. The largest number of eggs found in the 

 mouth of any one male was fifty-five, and numbers 

 above twenty were quite frequent. The habit of oral 

 gestation in catfishes of various species and from many 

 different geographical regions has, of course, long 

 been known, but the carefully ascertained details 

 recorded in the present paper will be much appreciated 

 by field naturalists. 



Mr. Gudger also contributes a memoin on the 

 Barracuda (Sphyraena barracuda), a well-known West 

 Indian fish of fierce and voracious habits, which is 

 much used as a food-fish. In the course of this 

 niemoir considerable space is devoted to a discussion of 



the occasionally poisonous character of this fish. As is 

 well known to West Indian residents, although the 

 flesh is generally a perfectly wholesome article of diet, 

 occasional specimens are met with which when eaten 

 cause serious illness, with symptoms which are con- 

 sidered distinct from those of ptomaine poisoning. 

 Although the author has been at some pains to collect 

 all the literature dealing with this poisoning, he has 

 failed to find any modern scientific account by a 

 medical writer, and it would appear to be a matter 

 which calls for a thorough investigation by those 

 interested in tropical disease. The fact of the oc- 

 currence of these cases has been quite familiar to 

 medical practitioners in the West Indies for many 

 years, but, judging from the information in the present 

 memoir, little progress has been made in discovering 

 the cause of the trouble. 



Another paper dealing with fishes is one by Mr. 

 C. F. Silvester on fishes new to the fauna of Porto 

 Rico. As a result of a three weeks' visit to the island 

 the author obtained eight species which he regards 

 as new to science, and the present communication is 

 devoted largely to a detailed description of these, illus- 

 trated by excellently coloured figures. 



Miss E. G. White deals with the origin of the electric 

 organs in Astroscopus guttatus, and gives a valuable 

 survey, with a ver)' complete bibliography, of the whole 

 question of the electric organs ot fishes, which should 

 be very useful to anyone seeking information on this 

 subject. 



Dr. Mayer himself contributes two short papers of 

 considerable importance. The first describes a series 

 of experiments on toxic effects due to high temperature, 

 in which a number of reef-corals were kept in warm 

 ocean-water for sixty minutes in the dark, and the 

 temperature was found which was just sufficient to 

 kill the coral. The author concludes that. " it seems 

 possible that death from high temperature may be due 

 to the accumulation of acid (possibly H2CO3) in the 

 tissues, the rate of formation of this acid being related 

 to the rate of metabolism of the tissues. Thus 

 animals of the same class having a high rate of meta- 

 bolism, as measured by oxygen consumption, are more 

 sensitive to heat and to CO2 than those having a low 

 rate of metabolism." Dr. Mayer's second paper is a 

 short note, in continuation of previous work, on nerve- 

 conduction in diluted and in concentrated sea-water, 

 the Scyphomedusa (Cassiopea xamachana) being the 

 animal used in the experiments, and the salinities 

 employed ranging from. 18-13 to 6096 per thousand. 



Mr. J. F. McClendon writes an important paper 

 on " Changes in the Sea and their Relation to 

 Organisms." Adopting the most refined modern 

 methods of analysis, he has studied a number of 

 physical and chemical problems which have a direct 

 bearing on the life of the plants and animals of the 

 sea. Amongst the problems dealt with are ocean cur- 

 rents, oxygen tension in sea-water, and the chemical 

 precipitation of calcium carbonate in sea-water, his 

 observations on the last-named being particularly sug- 

 gestive. 



Mention must also be made of Mr. S. C. Ball's 

 observations on the migration of insects to the Rebecca 

 Shoal light-station, an isolated station 105 miles from 

 the mainland of Florida and 95 miles from the coast 

 of Cuba. Mosquitoes and house-flies are the insects 

 chiefly discussed, and some striking figures are given 

 which have an imoortant bearing on the problem of 

 insect migration. Other papers are on amphibians and 

 reptiles from Porto Rico and the Virgin Islands by 

 H. W. Fowler, and on the botanical ecology of the 

 dry Tortugas by H. H. M. Bowman. Dr. Mayer is 

 to be congratulated upon a most interesting and im- 

 portant volume. E. J. A. 



NO. 2544, VOL. lOIJ 



