Feb. 4, 1 886 J 



NA TURE 



329 



Feb. 

 7 



7 

 7 

 7 



Phenomena of yupiter' s Satelliles 

 Feb. 



o o I. ecI. disap. 



O 38 II. tr. egr. 

 3 8 I. occ. reap. 

 2 3 I. tr. ing. 

 8 ... o 18 I. tr. egr. 

 8 ... 21 34 I. occ. reap. 

 The Occultations of Stars and Phepi 

 e visible : 



Satll 

 outer n 

 Feb. 

 7 • 



2 17 III. eel. disap. 

 5 II III. eel. reap. 

 5 40 III. occ. disap. 



3 43 II. eel. disap. 

 ... S 23 I. tr. ing. 



... 22 3 III. tr. egr. 

 lof Jupiter's Satellites are such as 



1, February 7. Outer major axis of outer ring = 45"'o ; 

 nor axis of outer ring = 2o"'l ; southern surface visible. 



h. 



6 ... Mars at greatest distance from the Sun. 



Variable-Stars 



R..\. 



Decl. 



U Cephei o 52-2 ... 81 16 N. ... Feb. ii, 22 19 m 



Algol 3 0-8 ... 40 31 N. ... ,, 8, 21 42 nt 



1 1, iS 31 »i 



A Tauri 3 54-4 ... 12 10 N. ... ,, 10, 23 51 in 



W Virginis 13 20'2 ... 2 47 S. ... ,, 8, o o M 



S Librje 1454-9... 8 4 S. ... ,, 11,2354™ 



U Coronce 15 13-6,.. 32 4 N. ... ,, 13, 3 5 m 



S Serpentis 15 i6'3 ... 14 43 N. ... ,, 8, M 



U Ophiuchi 17 lo'S ... i 20 N. ... ,, 8, 14 o m 



and at intervals of 20 8 



/8 Lyras 18 45-9 ... 33 14 N. ... Feb. 11, 9 30 M 



R Lyrte 18 51-6 ... 43 48 N. ... „ :o, m 



5 Cephei 22 24-9 ... 57 50 N. ... ,, 7, 21 30 la 



,, 13, 7 DOT 

 M signifies maximum ; 111 minimum. 



Meteors 

 There are no important periodical showers at this season of 

 the year. The following are amongst the principal radiants 

 front which meteors may be expected: — Near Capella, R.A. 

 75°, Decl. 44° N. ; three radiants in Ursa M.ajor, R.A. 131°, 

 Decl. 52° N., R.A. 180', Decl. 56° N., and R.A. 210°, Decl. 

 53° N. ; one from Corona Borealis, R.A. 226°, Decl. 30° ; near 

 i8 Herculis, R.A. 260°, Decl. 0°. February 10 is a fireball date. 



Stars with Remarkable Spectra 

 Name of Star R.A. 1S860 Decl. iSS6-o Type of 



72 Schjellerup ... 6 3 49 



ij Geminorum ... 6 8 o 



/» Geminorum ... 6 16 3 



78 Schjellerup ... 6 28 42 



LL 13412 6 49 12 



51 Geminorum ... 7 6 49 



lis Schjellerup... 8 48 57 



120 Schjellerup ... 9 3 46 



R Leo Minor ... 9 38 45 



R Leonis 9 41 26 



26 2-1 N. ... IV. 



22 32-4 N. ... in. 



22 37-5 N. ... III. 

 38 32-2 N. ... IV. 



23 46-8 S. ... Bright lines 



16 21-2 N. ... III. 



17 39-9 N. ... IV. 

 31 257 N. .. III. 

 35 2-1 N. ... III. 

 II 57-5 N. ... III. 



BIOLOGICAL NOTES 

 Metamorphosis in Nematodes. — Dr. von Linstow sums 

 up our present knowledge as follows : — The Nematelminthes, 

 according to the medium in which the individual developmental 

 stage is passed, present a truly wonderful series of metamorphoses, 

 and no less than fourteen distinct developmental stages may be 

 enumerated, (i) The embryo passes into an adult form direct 

 (without the intervention of a larval stage) in the one medium, 

 and also passes its existence in fresh, salt, or brackish water, 

 in plants, in the earth, or in decaying substances (Dorylaimus, 

 Enoplus, Plectus, Monhystera, Rhabditis, and many other 

 genera). (2) The larva; live in the earth, the adult form in plants 

 {TyUnchus tritici, T. putrefaciens, Heterodera schachtii). (3) The 

 larva; live in worms, and on their death and decay pass into the 

 earth, when they assume an adult form [Rhabditis pellio). (4) The 

 Helminth lives bise.xual in the earth, the fruitful females enter 

 the bodies of bees, and produce therein offspring (Sphicrularia 

 bombi). (5) The larva; live in the earth, assuming the adtilt con- 

 dition in some animal (Dochmius, Strongylus). (6) The Hel- 

 minth lives as an hermaphrodite form in some animal, the ofiT- 

 spring develop into bisexual forms in the earth (Rhabdonema, 

 Angiostomum). (7) Some adult forms difterentiate free-living 

 forms developing sexually, and also hermaphrodite forms living 



parasitically in animals (snails, Leptodera appendieulata). (8) 

 The larva" hatch out in the earth, and then enter some 

 animal, in which they become metamorphosed into hermaphro- 

 dite forms (Trichocephalus, Oxyuris). (9) The larvte live in 

 insects, the adult form in earth or water (Mermis). (10) 

 The larva; live encapsuled in some animal, and with it pass 

 into the digestive system of some other animal form, in 

 which latter they become adult (Ascaris, Filaria, CucuUanius). 

 (11) For a short time the hermaphrodite form lives in the intestine 

 of some animal, and produces here its larval form, which, pene- 

 trating the intestinal walls, makes its way into the muscles, 

 where it becomes encapsuled [Trichina spiralis). (12) The 

 adiilt form lives in the trachea; of birds ; the females lay eggs, 

 which contain well-formed embryos, which get expectorated, to 

 once again enter the bird's system with its ordinary nourishment. 

 In the crop and oesophagus of the bird the embryo hatches out, 

 wandering into the bronchi:e and air-sacs, from whence the 

 larger larva; find their wiy to the trachete [Syngamus trachealis). 



(13) There will be two larval forms, of which the one will be 

 found in Mollusca, and the other in aquatic beetles and water- 

 boatmen, while the adult form lives in v/Mev [Gordius aquaticus). 



(14) There will be two larval forms, of which the one will be 

 found in water, the other in the lung of some Amphibian, from 

 whence it will wander into the intestine of the same animal, 

 where it will develop into an hertnaphrodite form [Nematoxys 

 longicanda); this latter form is described and figm-ed. — [Zeitschri/t 



fiir wissenschaftUche Zoologie, Noveaiber 24, 1885, Band xlii. 

 Heft 4, p. 715, pi. 28.) 



Artificial Propagation of Oysters.— Mr. \V. K. Brooks 

 calls attention in detail to a very important fact in the artificial 

 propagation of oysters to which his notice was first called by 

 Mr. W. Armstrong, of Hampton, Virginia. It would appear 

 that "seed" oysters which Mr. Armstrong had placed on 

 "floating-cars" in the mouth of Hampton Creek not only 

 grew more rapidly, but were of a better shape, and therefore 

 more marketable, than those from seed deposited at the same 

 lime in the usual way on the bottom. Immediately after the 

 embryo oyster acquires its locomotor cilia there is a period of 

 several hours, when it swims at the surface, and this is the 

 period when it is swept into contact with collectors. As soon 

 as the shell appears, the larva is dragged down by its weight, 

 and settles at the bottom. The greatest danger to which it is 

 now e.xposed is that it may not at this stage of its existence 

 find a hard, clean surface for attachment. Being of micro- 

 scopical dimensions, it may be smothered by a deposit of sedi- 

 ment or mud so light as to be invisible, and most of the failures 

 to get a good "set of spat " are due to the formation of a coat 

 of sediment upon the collectors before the young oysters come 

 into contact with them. This danger seems to be entirely 

 avoided by the use of floating collectors, for little sediment can 

 fall on a body which is close to the surface of the water, and 

 most of what may fall will be swept off by the currents which 

 bring the swimming embryo oysters into the collectors. The 

 collector employed by Mr. W. K. Brooks was formed by con- 

 necting two old ship-masts together by string pieces, with a 

 bottom of coarse galvanised iron netting which had buoyancy 

 enough to support a large quantity of submerged shells. Such 

 floats should be open at the ends to permit free circulation, and 

 should be so moored as to sway with the current. Mr. Brooks 

 moored a collector, on July 4, in front of the Zoological Labora- 

 tory at Beaufort, N.C. Although all the oysters in the vicinity, 

 from being in very shallow water, were nearly through their 

 spawning season, and the conditions were anything but favour- 

 able, yet there was immediately secured a good "set," and the 

 young oysters grew with remarkable rapidity, no doubt on ac- 

 count of the abundant supplies of food and fresh water, which 

 gained ready access to all of them, and the uniform temperature 

 which was secured by the constant change of water. The im- 

 portance of this suggestion is obvious : this method may be used 

 by planters to collect their own supply of seed — an object of great 

 importance — when the feeding regions are far removed from native 

 beds. Perhaps time will prove that it may be also used for 

 rearing the oyster to a stage making it fit for the market ; when, 

 if so, the better shape and firmer shell would give the supply 

 thus raised a superior value. Even in j^laces where there are no 

 oysters near to furnish the supply of eggs, a few spawning- 

 oysters could be placed among the shells in the collector, after 

 the French method, to supply the "set." Though, as Mr. W. 

 K. Brooks says, " Engagement in business projects is no part 

 of the [direct] office of a University," still, we venture to hold 



