April 22, 1892,] 



SCIENCE. 



229 



oiss dark blotches and short stripes, especially on the wings. 

 This species appears to be double-brooded in the latitude of 

 Iowa, though it is possible that three broods may occur. 



The habit these insects have of hopping into the air on 

 the least disturbance renders them open to direct attack with 

 the " hopper-dozer " principle, which has been used so exten- 

 sively in the contests witb the Rocky Mountain Locust. 



We have found, however, that a very simple plan of using 

 this principle is the most effective in securing the leaf-hop- 

 pers. It consists in coating the upper surface of a sheet of 

 sheet-iron with coal tar, attaching cords at either end, and 

 also in the centre if it is very long, with which to draw it, 



Agallia sanguinolenta: A. larva; B. pupa; C. imago, and front view ol head 

 of imago. (Original). Size lines are a Ifttle too long. 



and then it is drawn over the lawn or pastui'e at a moderate 

 walk by a boy or man at each end. 



As soon as the sheet becomes covered with hoppers so that 

 all are not held when they strike the pan a new coat of tar is 

 applied. On an extensive scale this can be used at a cost 

 of but a few cents per acre, and is applicable to large 

 pastures and meadows. Upon lawns and pastures the treat- 

 ment may be applied at any lime when the hoppers appear 

 numerous, but in meadows it is not applicable while the 

 grass is in bloom on account of the accumulation of pollen 

 on the sheet. In general, the best time to apply it is in early 

 May and again, if hoppers are present, in summer, directly 

 after the hay-crop has been secured. Herbert Osborn. 



Ames, Iowa. 



ASTRONOMICAL NOTES. 

 The following is an ephemeris for the comet discovered by 

 Denning on March 18. The epoch is for Berlin Midnight: — 

 R.A. Dec. 



h. m. s. o ' 



April 25 2 18 44 -^- 58 5.8 



26 23 16 57 53.7 



27 27 43 57 41.4 



28 32 5 57 28.8 



29 36 23 57 15.9 



30 40 36 57 2.8 

 May 1 44 45 56 49.5 



2 48 49 56 36.0 



3 52 49 56 22.2 



4 2 56 45 56 8.3 



5 3 37 55 54.2 



6 3 4 24 55 54.2 



7 3 8 8 +55 25.6 

 This comet is now increasing its distance from the earth, 



but in the auiumn the comet will again approach the earth, 

 and observations will be possible far into next December. 



The following is an ephemeris for the comet discovered on 

 March 6 by Dr. Swift of Rochester, N.Y. The epoch is for 

 Berlin midnight: — 



E.A. Dec. 



h. m. s. o ' 



April 25 22 14 21 + 16 10.0 



26 17 30 16 57.9 



27 20 37 17 45.0 



28 23 42 18 31.2 



29 26 46 19 16.6 



30 29 48 20 1.2 

 May 1 22 32 49 20 44.9 



2 35 48 21 27.8 



3 38 43 22 9.8 



4 41 42 22 51.0 



5 44 36 23 31.4 



6 41 29 24 ILl 



7 22 50 20 + 24 50.0 

 These ephemerides are taken from No. 3,082 of the Astr o 



nomische Nachricliten. That for comet Swift was computed 

 by Dr. Lamp, and that for comet Denning by Dr. Schorr. 



The new star in Aurigae has now become so faint that it 

 can be observed only in the larger telescopes. It is fainter 

 than the 13th magnitude. G. A. H. 



NOTES AND NEWS. 



Me. G. C. Green records in Nature Notes for April a cur- 

 ious reminiscence with regard to a pair of jackdaws kept by him 

 at Modbury Vicarage, South Devon, about twenty years ago. 

 They had been taken from the nest, and during the first summer 

 their wings were sh'ghtly clipped. After this their wings were 

 allowed to grow, and they lived at full liberty in the garden. 

 They were perfectly tame, and would come at call and feed out 

 of the hand, would come into the house, and in the morning 

 knock at the windows to ask for some breakfast. In the spring 

 they used to fly away and join their wild companions, make thfir 

 nests, and rear a family; but when this was over they came back 

 to the garden again, fed from the hand, and were as tame as ever. 

 But the curious thing was, that after one or two seasons they 

 brought another jackdaw with them, presumably the youn^ of 

 one of them, which was just as tame as themselves, although 

 nothing had ever been done to tame it, so that it was impossible 

 to tell which were the original favorites, and which was the new 

 one. Moreover, when after a few years one of these jackdaws 

 was accidentally killed, another was brought by the other two. 



— A Seaside Laboratory of Natural History, in connection with 

 the Leland Stanford, Jun. , University, will be opened during; the 

 coming summer at Pacific Grove, Cal. , on the Bay of Monterey, 

 about half-way between Monterey and the Point of Pines. This 

 laboratory will be for the purposes of investigation in tlie life- 

 history of the marine animals and plants of this coast. It will be 

 under the direction of Professors Gilbert, Jenkins, and Campbell 

 of the chairs of zoology, physiology, and botany respect! vel}'. It 

 will be open to naturalists and others wishing to make special in- 

 vestigations in the anatomy or life-history of animals and to teach- 

 ers of natural science. For further details those interested may 

 apply to any of the directors at Palo Alto, Cal. 



— In a discussion on diphtheria, published in the British Medi- 

 cal Journal for Sept. 19, 1891, Dr. Russell cited several instances 

 in which steam had seemed to be an active factor in the propaga- 

 tion of the disease. Hot water and steam from a brewery were 

 introduced into some old cesspools and evidently waked into ac- 

 tivity germs which, if undisturbed, would have remained dor- 

 mant. 



— A new edition of S. Dana Horton's " Silver in Europe"' will 

 be published immediately by the Macmillans. The author has 

 made some additions of importance to this edition in view of the 

 present attitude of Congress on the question of free silver. 



