45 



NATURE 



[March 9, 1916 



OUR ASTRONOMICAL COLUMN. 



The Solar Activity. — Sun-spot activity has been 

 especially noteworthy during the past few days, a 

 feature being the great extent and disturbed character 

 of several of the groups. 



Comet 1916a (Neujmin). — The discovery of the first 

 comet of the year by M. G. Neujmin, of the Simeis 

 Observatory, Crimea, on February 24 was announced 

 last week. According to a telegram received last 

 Friday from Prof. E. Stromgren, the comet was ob- 

 served by Prof. Biesbroeck (Ycrkes) on February 29, at 

 i4h. 4i-3m. G.M.T. ; its position was R.A. 8h. 58m. 

 46-58., declination +13° 35' 14". The comet is thus a 

 little south of k Cancri. 



Comet 19156 (T.-wlor). — On February 4, 1891, Dr. 

 Spitaler, searching for Winnecke's comet, observed a 

 cometic object that afterwards could not be refound. 

 On the basis of the orbit calculated by M. J. Braae 

 and Mile. J. Vinter Hansen, Prof. A. Berberich finds 

 (Astronomische Nachrichteti, No. 4827) that this soli- 

 tary observation possibly refers to comet Taylor. 

 Assuming changes of +65° and —6-3° in longitudes of 

 node and of perihelion respectively, and calculating 

 the comet's place for M=5i°, gives about the position 

 of the object seen by Dr. Spitaler. Decided alterations 

 in the position of the nodes due to perturbations by 

 Jupiter were possible in 1901, and again in 1912-13. 

 If perihelion occurred in 18910, then the interval, 

 25-1 years = 4X6-27, would be equivalent to four revolu- 

 tion's. Dr. Spitaler recorded that at about g^h. he saw 

 the object "between the faint stars lying together in 

 the same parallel 20s. preceding the star DM + 26°, 

 1714," i.e. R.A. 7h. 58m. 43s., declination 26° 15'. 

 This position was in fairly close agreement with that 

 calculated for Winnecke's comet according to the orbit 

 of von Haerdtl. 



The Orbit of VV Orioms.^A paper by Mr. 

 Zaccheus Daniel (Publications, Allegheny Observa- 

 tory, vol. iii., No. 21) deals with this eclipsing variable 

 and spectroscopic binary. Chief interest centres in the 

 fact that situated within 1° of 8 Ononis it is now 

 found to present the same spectral peculiarity, the 

 calcium K line not sharing the oscillations shown by 

 the lines of other elements. Its spectrum is of the 

 B2 type, and the lines are generally diffuse. The 

 period, 1-4854 da3-s, agrees with that previously found 

 by Hartmann from photometric observations, but this 

 rapid oscillation is superposed on a slower, having a 

 period of 120 days. The velocities given by the 

 K line are not quite constant, hence possibly the 

 calcium atmosphere belongs to the system, and has 

 an orbital movement in the same direction as the 

 brighter component. The mean value from the K 

 line is +16-7 km. /sec, agreeing with the mean for 

 8 Ononis (+17-2) and e Ononis (+15-6), and with the 

 value of the sun's motion away from that part of 

 space. Thus the calcium vapour is stationary, but as 

 the early type stars themselves have very small veloci- 

 ties, the pres.ent evidence does not settle whether the 

 calcium belongs to the stars or not. 



Observations of Variable Stars. — Dr. C. Hoff- 

 meister {Astronomische Nachrichten, No. 4827) 

 has recently published a considerable collection 

 of observations of many Algol and short-period vari- 

 ables, and also of a numter of suspected variables. 

 Among the latter is t] Ursae Majoris, for which the 

 present observations indicate a range of 0-3 magnitude. 

 Dr. G. Hornig (Astronomische Nachrichten, No. 4828) 

 gives dates of maxima and minima of (j) Persei 1 

 observed during November, 1914-April, 1915. The 

 period of the latter star is found to be i8-t days, very 

 nearly one-seventh that found by Lau. Maxima date 



NO. 2419, VOL. 97] 



_ from November 28, 1914, and thus the next would be 

 due March 12. The variation is of the Cepheid type 

 (M-7n=:7-5 days). Observations of 7 Arietis, 15 Tri- 

 anguli, and 31 Orionis show them to be irregularly 

 variable in periods of about 70, 200, and 356 days 

 respectively. 



SEA-SPIDERS AND FEATHER-STARS.^ 

 F^R. CALMAN reports on the Pycnogons or sea- 

 ^-^ spiders collected by the British Antarctic Expedi- 

 tion of 1910. The collection far exceeds that of any 

 Antarctic expedition yet reported on, comprising no 

 fewer than forty-four species, eleven of which arc new. 

 There seems no doubt that Antarctic seas are far richer 

 in these quaint, slow-living creatures than any other 

 area of the oceans. While most of the species were 

 obtained in very small numbers, this was not always 

 the case, for we read that two hundred specimens of 

 Nymphon australe were obtained at a single station, 

 and presumably at a single haul. 



The author discusses the meaning of the ten-legged 

 species which occur, the great majority being eight- 

 legged, and defends, against Prof. Bouvier, the view, 

 which he shares with Prof. Carpenter, that the deca- 

 podous Pycnogons represent a recent specialisation, 

 not a primitive survival. An interesting parallel is 

 found in Pliotrema, a Pristiophorid shark, described 

 by Mr. C. Tate Regan, which has six gill-arches in- 

 stead of the usual five, but is evidently a very highly 

 specialised form, derivable from some ancestor like 

 Pristiophorus, with the normal number of arches. 



Attention has been directed to the great range of 

 variability in sea-spiders, but Dr. Caiman does not 

 think that it is greater than, for instance, in many 

 groups of Crustaceans. And as to the theory of 

 Doderlein, that lack of the power of wandering is a 

 factor which favours the development of local races, 

 varieties, and species in any group of animals, the 

 author finds no corroboration in the case of Pycnogons, 

 which are extremely slow-going creatures. Although 

 some species can swim in the adult state, their efforts 

 seem to be awkward and ineffective, and none of the 

 larvae are better adapted for locomotion. The memoir 

 is marked by Dr. Caiman's well-known carefulness of 

 workmanship, and the illustrations drawn by Miss 

 Gertrude M. Woodward are remarkably fine. 



Mr. A. H. Clark is to be congratulated on the 

 appearance of the first part of the monograph on 

 present-day Crinoids, to which he has largely devoted 

 his energies during the last ten years. The study of 

 these singularly beautiful animals has been heretofore 

 dominated by the palasontological approach, and not 

 unnaturally, since the fossil record is extraordinarily 

 complete, and not very many recent forms have been, 

 known or have been available for investigation. 

 This, as the author says, has led to " the recent 

 Crinoids being considered as the impov-erished 

 and decadent remnants of a once numerous and 

 powerful class, the last forlorn and pitiful expo-- 

 nents of a dwindlinsr phylogenetic strain. During the 

 1906 cruise of the Albatross I handled tens of thousands 

 of specimens ; several times I saw the forward deck 

 of the steamer literally buried under several tons of 

 individuals belonging to a species exceeding any fossil 

 form in size ; everywhere we went we found Crinoids ;. 

 we dredged them at all depths." 



1 " British Museum (Nnural H-storv). Britisli Antarctic (/"^-rrrt .A 

 F.xpedition, iqio *^'atural Historv Rep-irt. Zoolog-, vol. iii.. N'. 

 Pycno'onida." Bv Dr. W T f"alin«n. Pn. 1-74+22 figs. (London : 

 Briti'ih Museum (Natu'al H''sfory\ tqi'.) P'ce 5^. 



Smit*":onian Institution. U S National M'-sei'm, Bulletin 82. "A Mono- 

 praph of the Existing Crino'Hs." By A. H. C'ark Vol. i. The ComatiiJirf.';. 

 Parti. Pp. 1-406+ 17 plates+513 figs. (Wa^hlngto^ : Government Printing' 

 Office, 1915.) 



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