ISIOV, 2 2, 1877] 



NATURE 



63 



sugar boiled together, to which (after boiling) is added a little 

 spirit, placing rags several folds thick, saturated in the pre- 

 paration, upon garden-seats, low branches of trees, &c. I have 

 in one evening taken as many as thirty-six moths (including red-, 

 yellow-, crimson-underwing, swordgrass, angleshade, &c., &c.). 

 What has attracted them unless smell ? or what generally leads 

 them to their food ? 



With reference to the sound of the glass, is it not the quick 

 motion of the hand which disturbs the moth ? E, H. K. 



Carnivorous Plants 



Prof. Serrano Fatigati, of Ciudad Real (Spain), has made 

 some investigations upon two insect-feeding plants which he 

 found during his last excursion to the province of Cordova, and 

 on the general peculiarities of viscous plants during their flower- 

 ing. The first of these plants is Ononis natrix ; it grows at Sierra 

 Palacios. The second appears to be Sdene viscosa, and was found 

 on the hill which connects the village of Belmery with the station. 

 The experiments made upon these plants prove that when alive 

 they were both covered abundantly with a viscous fluid, which in 

 Silent was still visible after the specimens had been dried for 

 four months. Prof. Fatigati has observed in several instances 

 that every insect which touches their surface, and remains 

 adherent to them, dies in a very few minutes. Remains of ani- 

 mals in different stages of decomposition may be seen on the 

 plants he possesses. 



The microscopical study of these plants has enabled the struc- 

 ture of their secretory glands to be examined. The glands of 

 the plant Ononis are at the extremity of hairs composed of cylin- 

 drical cells, and are ovoid and multicellular. The protoplasm 

 of the cylindrical cells always forms a parietal coating to the 

 cell-wall. The glands of the Silene are simply conical epider- 

 mical protuberances, and are divided into two cells at the close 

 of their development. 



Prof. Serrano Fatigati has observed that in these species and 

 in Cistus ladaniferus the secretion of the viscous fluid increases 

 during their period of flowering ; he is studying this matter, in 

 order to ascerta-n whether this circumstance bears any connec- 

 tion with the production of heat and carbonic acid possessed by 

 plants during the flowering period. Francisco Ginez 



Espar;eros 9, Madrid 



OUR ASTRONOMICAL COLUMN 

 Minor Planets. — Mr. J. N, Stockwell, of Cleveland, 

 Ohio, who has had much experience in calculations re- 

 lating to the small planets, draws attention to a curious 

 circumstance connected with the observations of Gerda, 

 discovered by Prof. Peters at Clinton, N.Y., on July 31, 



1872. It had been supposed that this planet was ob- 

 served again in 1873, 1876, and 1877, but on forming 

 equations of condition for the correction of the elements, 

 Mr. Stockwell found that the observations of 1873 are 

 quite irreconcilable with those of the other opposition?, 

 or that some incompatible conditions had been introduced 

 into the equations. " The discovery of these incom- 

 patible conditions," he writes, " has been the occasion of 

 an unusual amount of trouble and annoyance, and will be 

 the source of future mortification, should the explanation 

 at which I have arrived ultimately prove to be erroneous." 

 Mr. Stoukwell's conclusion is this, that notwithstanding 

 the planet observed from September 27 to November 12, 



1873, was very near the computed place of Gerda, it was 

 really another body that was observed in that year. To 

 decide this point he calculated an orbit upon the observa- 

 tions of 1873, which it appears are very well adapted to 

 furnish reliable results, and finds the following elements, 

 placing the elements of Gerda, as perturbed to the same 

 date, in juxtaposition for the sake of comparison. The 

 epoch is 1873, November 7*0 M.T. at Washington, longi- 

 tudes from M.Eq. i873'o : — 



Planet of 1873. Gerda. 



Mean long. 



35 4 57 



213 14 38 



178 53 9 



I 36 3 



I 58 40 



6i3"-6390 



35 47 14 

 208 19 29 

 178 56 40 



1 36 19 



2 o 51 

 6 14" -3842 



It will be seen that four of the elements of the planet of 

 1873 are almost identical with those of Gerda, while the 

 lines of apsides differ about five degrees. The actual 

 distance of the planets from each other on November 7 

 would be 00188 of the earth's mean distance from the 

 sun. Mr. Stockwell adds, " if there are really two planets 

 moving in orbits so extremely near together, it must 

 happen in the course of time, unless the mean distances 

 are exactly the same, that they will approach each other 

 so closely that their mutual perturbations will cause them 

 to unite and form a single planet." 



A similar case of near coincidence between the orbits 

 of two minor planets is that of Fides and Maia, to which 

 attention was first directed we believe by M. Lespiault, of 

 Bordeaux. In 1876 the elements were as follow : — 



Epoch .. 

 Mean long. 



Fides. 

 July 27-0 Berlin^M.T. 



- 326 33 33 ••• 

 66 27 20 



... 8 15 15 ... 

 3 6 49 ... 

 10 II 21 

 826" "441 7 



Maia. 

 Oct. 4-5 Berlin M.T. 



... 2°7 37 21 

 ... 48 8 26 



8 17 I 



3 5 40 

 ... 10 4 31 

 824" -6400 



Here, however, the planets are much further from each 

 other than in the case of Gerda and the planet of 1873. 



At present Gerda and its companion will not be favour- 

 ably placed for observation, but in the ensuing year no 

 doubt an effort will be made to decide if there are really 

 two bodies revolving in such near proximity to each 

 other. Questions of much interest may arise if this 

 should prove to be the case. 



The discoveries of minor planets during the present 

 year now stand as follow : — 



No. 170, Myrrha, January 10, by Perrotin, at Toulouse. 

 ,, 171, Ophelia, January 13, by Borrelly, at Marseilles. 

 ,, 172, Baucis, February 5, ,, ,, 



.. 173. August 2, „ „ 



M 174. September 2, by Watson, at Ann Arbor, U.S. 



M 175. October 14, by Peters, at Clinton, U. S. 



M 176, November 5, by Paul Henry, at Paris. 



M 177. November 6, by Palisa, at Pola. 



A planet, November 12, by Watson, at Ann Arbor. 



We adopt Prof, Peters' name for No. 170, instead of the 

 inappropriate one proposed in France. 



The Comet of 1672.— Madler has pointed out a 

 distant resemblance between the elements of the comet of 

 1672 calculated by Halley, and those of the comet of 

 1 81 2, which has been found to have a period of revolution 

 of about seventy years, and which therefore might h tve 

 been in perihelion in the former year. The comet of 

 1672 was observed by Hevelius from March 6 to April 21, 

 and also by Richer off the coast of Africa during his 

 voyage to Cayenne, from March 15 to the end of the 

 month, though he only described its position roughly. 

 The observations of Hevelius are published in the rare 

 volume of his " Machina Ccelestis " (of which, by the 

 way, the British Museum possesses two copies), and we 

 believe in the small special publication issued at Dantzig 

 in the same year, and entitled, " J. Hevelii, Epistola de 

 Cometh, anni 1672, Gedani observato, ad Henricum 

 Oldenburgium," 



Halley's orbit gives for three dates of observation by 

 Hevelius, adopting his corrected times, the foUo*ving 

 positions : — 



G.M.T. R'ght Ascension. Deciination. 

 h. m. o / o ' 



1672, March 6, at 15 39 ... 353 16 ... 34 57 N. 

 „ 15, at 7 44 - 18 2 ... 3725 

 „ ,, 29, at 8 8 ... 5221 ... 30 21 N. 

 Without attempting an accurate reduction of the 

 Dantzic observations, it may be seen that they agree 

 sufficiently well with the positions deduced from Halley's 

 orbit to render it probable that his elements would not be 

 so far changed by a calculation from the improved places 

 as to bring them materially closer to those of the comet of 



