Nov. 15, 1888] 



NATURE 



61 



The Sebastopol Biological Station, under Dr. Sophie 

 Pereyaslavtseva, continues to bring out important biological 

 works. In the last number of the Bulletin of the Moscow 

 Society of Naturalists (1888, No. 2), Mrs. Pereyaslavtseva 

 publishes (in French) the first instalment ofa most valuable work 

 which she has written in association with Miss Marie Rossiiskaya, 

 on the embrj'ogeny of the Amphipods, being a continuation of 

 lier previous studies in the embryogeny of Rotifeis. The de- 

 velopment of Gammartis fa-cilurus is described in the first part 

 of the work, and an idea of its detailed character may best be 

 given by mentioning that the various stages of development of 

 that one species are illustrated by no less than one hundred and 

 twenty microscopical sections beautifully printed in colours. Two 

 more representatives of Amphipods {Caprella and Orc/ieslia) ha.ve 

 been studied in the same way, while the lady students who work 

 at Sebastopol under the learned lady-director of the station are 

 now studying other species of Amphipods, and especially of 

 Gammarus ; so that a complete work on the embryogeny of that 

 important zoological division is expected to be ready by the end 

 of the autumn. For the present, Mrs. Pereyaslavtseva refrains 

 from suggesting general conclusions, but at the end of her 

 monograph she points out that throughout the embryonal 

 development of Gammarus pacilurus the cells of its tissues are 

 endowed with amoeboid movements. Those movements are 

 less pronounced in the ectodermic and mesodermic layers, and 

 yet the cells of the former are moving and protruding pseudo- 

 pods even when the endodermic " layer has taken the shape 

 of a fully formed pouch, and its constitutive cells may be 

 considered as epithelium. As to the cells of the mesoderm, 

 they maintain the capacity of both locomotion and overlapping 

 {chci'auchevicnt) even at very advanced stages of the develop- 

 ment of the embryo — that is, until the elaboration of the muscular 

 tissue has been completed. These phenomena have been noticed 

 in all the three genera of Amphipods already studied, and most 

 probably they are common to all Amphipods. 



Messrs. Marion and Co. send us an account ofa " detective 

 camera " which has been planned to meet the requirements of 

 the inexperienced as well as the experienced in photography. It 

 has the appearance of a leather dressing-case or despatch-box, 

 and has the special advantage that the person using it sees the 

 exact picture he is to get on his plate, the same lens giving the 

 image on the screen and taking the negative. Another 

 "detective camera" of which Messrs. Marion and Co. have 

 issued a description is in the form of a book, and can be used 

 secretly, since there is nothing to indicate its real purpose. 



In an article on "Irregular Star Clusters" (Nature, 

 November i, p. 13), it was stated, with regard to an apparent 

 member ofa scattered group in Ophiuchus, that its position "was 

 found, by the comparison of photographs taken by M. von 

 Gothard in 1886 with Vogel's measures of eighteen years pre- 

 viously, to have changed to the extent of 45", or at the rate of 

 2i" annually {Astr. Nach., No. 2777)." Dr. H. Kreutz, of 

 the Kiel Observatory, writes to us to say that more recent 

 measures of Dr. B. von Engelhardt {Astr. Nach., No. 2859) 

 have proved this to be incorrect. The difference between 

 Gothard's photographs and Vogel's measures was due to an 

 error in Vogel's work. 



The additions to the Zoological Society's Gardens during the 

 l)ast week include two White-tailed Eagles (Halurtus albicilla), 

 British, presented by Mr. R. H. Venables Kyrke ; two Short- 

 eared Owls (^Olus brachyolus), captured in the Red Sea, pre- 

 sented by Captain John Marr ; a Little Grebe {Tachybaptes 

 fluviatilis), British, presented by Mr. Howard Bunn ; two 

 Spotted Ichneumons {Herpestes mpaUnsis i i), an Indian 



Otter (Lutra nair <J ) from India, a Sclavonian Grebe {Podiceps 

 aurilus), British, deposited ; four Knots ( Tringa canuius)^ 

 European, purchased. 



OUR ASTRONOMICAL COLUMN. 



The Total Solar Eclipse of August 29, 1886.— Part 5 of 

 vol. xviii. of the Annals of the Harvard College Observatory, con- 

 tains an account by Mr. W. H. Pickering of his expedition to 

 Grenada in 1886 in order to observe the total eclipse of August 

 29 ; and some points in his report have recently been commented 

 on by Mr. W. H. Wesley {Observatory, October 1888) and 

 Mr. Ranyard {Knowledge, November 1888). Mr. Pickering's 

 original plan of work had been a very wide one, and he took out 

 a great variety of instruments with him, but no assistants besides 

 his wife and a lady friend. It was very late in August before he 

 arrived at Grenada, and this circumstance and the frequent 

 obscuration of the sun before totality on the day of the eclipse 

 caused several items of his programme to result in complete failure. 

 The long focus photoheliograph and the actinometer under 

 Mr. Pickering's own Superintendence gave no results, but Mrs. 

 Pickering secured three photographs with a couple of short-focus^ 

 cameras, and Mr. Glean one with a telescope of 4 feet focus. 

 One of Mrs. Pickering's photographs supplies some very curious 

 features in the shape of some very faint extensions of the corona 

 on the western side of the sun. One of these is a prolongation 

 of a bright synclinal mass, and rises in a narrow jet to a height 

 of 48' from the limb, and then divides into three parts, two- 

 falling back towards the sun right and left of the centre ray, 

 which attains a total height of 60', then to bend over in a pre- 

 cisely similar fashion. Another extension further to the north 

 rises to abottt the same height, 60', and then curves downward 

 again. 



Mr. Pickering's spectrum photographs afforded little fresh in- 

 formation, but confirmed Prof. Tacchini's observation of " white " 

 prominences ; and two of his small coronal photographs were 

 used to give a determination of the brightness of the corona. 

 These gave the total actinic brilliancy of the corona with the sur- 

 rounding sky as 700 units, or ten times that of the full moon with 

 surrounding sky. But the intrinsic actinic brightness of the 

 brightest part of the corona was only 0*03, whilst the average 

 intrinsic brightness of the sky 1° from the sun on a fine day was 

 determined to be 1200 times as great. 



Comet 1888 / (Barnard).— Dr. R. Spitaler has computed 

 the following elements and ephemeris for this comet from 

 observations made at Mount Hamilton, October 30, at Vienna, 

 November 2, and at Hamburg, November 5 : — 



T = 1888 September 10-82914 Berlin M.T. 



TT = 65 012) 



ft = 137 34 17 .- Mean Eq. i888-o. 

 « = 55 17 10) 

 \ogq = O" 16873 



Error of middle place (O - C). 



A\ cos /3 = - 4" J A)8 = o. '. 



Ephemeris for Berlin Midnight. 



1888. R.A. Decl. Log A. Lor r. Bright- 



h. m. s. o / ness. 



Nov. 16 ... 10 5 37 ... 12 25-4 S. ... 0-2197 • • 0-2414 ... 0-96 



20... 10 956... II 34-3 ...0-2141 ... 0*2487 ... 0-95 



24 ... 10 13 50 ... 10390 ... o-2o8i ... 0-2561 ... 0-94 



28 ... 10 17 46 ... 9 382 S. ... 0-2018 ... 0-2636 ... 0-94 

 The brightness at discovery is taken as unity. 



ASTRONOMICAL PHENOMENA FOR THE 

 WEEK 1888 NOVEMBER 18-24. 



/"pOR the reckoning of time the civil day, commencing at 

 ^ Greenwich mean midnight, counting the hours on to 34, 



is here employed. ) 



At Greenwich on November 18 

 Sun rises, 7h. 26m. ; souths, iih. 45m. 26-os. ; sets, l6h. 4m. : 



right asc. on meridian, I5h. 37-210. ; decl. 19' 25' S. 



Sidereal Time at Sunset. I9h. 57m. 

 Moon (Full on November i8, I5h.) rises, 4h. 32m.; souths, 



oh. 5m.*; sets, 7h. 49m.*: right asc. on meridian, 



3h. 59 "Sm. ; decl. 16° 30' N. 



