Sept. 1, 1S66.J 



HARDWICKE'S SCIENCE-GOSSIP. 



215 



Hawthorn Caterpillar.— Although the larva 

 of Hyponomeuta padella may be the insects which 



strip the leaves of the hawthorn, &c. (see Science 

 Gossip, p. 1S2) in the south of England, I believe 

 that in the northern counties it is mostly caused by 

 a totally different species, viz., the Winter niotli 

 {Cheimatobia brumatd) ; it not only eats the haw- 

 thorn, but almost every other tree ; in fact, with the 

 assistance of the larva of the green oak-moth (Tor- 

 trix viridana), whole woods of oak often appear 

 quite withered and bare from its ravages. — 67. T. 

 Forrett. 



Thistle Galls. — These were illustrated and de- 

 scribed in the Gardener's Chronicle for 1S17, p. S15. 

 They are produced by a small dipterous insect called 

 Musca (Tephritis) Cardui. 



Ice-Birds. — In Lord Dufferin's "Letters from 

 High Latitudes," p. 319. he speaks of "Ice-birds." 

 Can any one tell what they are ? — Bangalore. 



Snails in Aquaria.— All the little shells in my 

 acpiarium have become corroded and whitened, and 

 so thin, that the least touch crushes them. The 

 water is pure, and the growing plants in full vigour. 

 What is the cause ? -E. H. IF. 



Gtjano a Poison. — A peasant cutting wood, 

 says the Gazette de Lausanne, was wounded by a 

 splinter, and having afterwards worked in guano, 

 this substance entered the wound and occasioned 

 death by poison after three clays' suffering ; this 

 fact should be known by all the people working in 

 docks unloading guano ships, &c. What precedes 

 reminds me of a case which may be attended also 

 with dreadful consecjuences for the labourers in the 

 docks. Sometimes the Buenos Ayres hides are im- 

 pregnated with a special drug to preserve them 

 better. A powder is sold for that purpose by the 

 Buenos Ayres apothecaries, w : hich is composed of 

 very toxic substances; workmen should then take 

 the utmost care to avoid inhaling the reddish-white 

 dust of those hides. — B. M. 



Carbolic Acid. — A very minute quantity of a 

 weak solution was added, under the microscope, to 

 water containing various infusoria. The acid proved 

 instantly fatal, arresting the movements of the ani- 

 malcules at once. Caterpillars, beetles, crickets, 

 fleas, moths, aud gnats were covered with a glass, 

 the inside of which was smeared by carbolic acid. 

 The vapour proved quickly fatal. It allays the pain 

 caused by the stings of bees, wasps, hornets, and 

 gnats, if applied pure, or in strong solution, to the 

 wounded part. Erom the intense aversion shown 

 by all insects to the odour of carbolic acid, it is 

 probable that the plentiful use of this agent would 

 effectually preserve cattle from those terrible 

 scourges met with in certain parts of Africa, the 

 zimb and tsetse-ily. — Crooked Application of Disin- 

 fectants, $x. 



Laurel Pimples. — What is the little pimple- 

 like, rosy-red formation on the young leaves of the 

 laurel ? Ants tap it with their antennae, and feed 

 on the exuding liquid as they do ou Aphis-honey. — 



f. jr. 



Organisms in CnALK.— There are very many in- 

 teresting small organic remains in chalk, which 



may be obtained by any one with a very small 

 amount of trouble. 



The following slight modification of the plan re- 

 commended in the Geologist (1863, p. 331) seems to 

 bethe best mode of procedure. Take a lump of chalk 

 about a pound in weight (which maybe procured in 

 almost every village shop) and with a stiff brash, 

 such as a nail-brush r rub away the surface in a bowl 

 of water, into which a gentle stream is continually 

 i running. As the larger foraminifera and other 

 organisms appear on the surface of the chalk, 

 they_ should be carefully detached, and suffered to 

 fall into the water. When a sufficient amount of 

 chalk-rubbing has been procured, it should be gently 

 stirred, and the small portions of chalk crushed 

 between the finger and thumb, then washed re- 

 peatedly until all milkiness disappears. The grey- 

 coloured residuum should then be thoroughly dried, 

 and sifted through small sieves, which may be readily 

 made by stretching muslin of different degrees of 

 fineness over rings of wood about two inches in 

 diameter. The coarser muslin should retain only the 

 larger foraminifera, the valves of entomostraca, and 

 other larger objects. The finer should permit only 

 the very finest dust to pass through ; and the re- 

 mainder will consist almost entirely of foraminifera. 

 Before mounting these in balsam, in the ordinary 

 manner, they should be placed in a watch-glass, with 

 a small quantity of oil of turpentine, and washed by 

 means of a camel's hair pencil several times, until 

 all chalkiness is got rid of, or the slide will not be 

 satisfactory. 



By proceeding in this manner, many of the larger 

 objects are preserved, which would be destroyed, if 

 the chalk were scraped or pounded. — /. S. Tide. 



The Edible Crab {Cancer pagur us). — One of 

 these crabs cast its shell in the Hamburg Aquarium, 

 June ISth, 1SG6, and the following are the measure- 

 ments : — 



Length of carapace before exu- 

 viation . . 4^ inches. 



Length of carapace after exu- 

 viation 5fly „ 



Increase of length 0^, „ 



Rate of increase of length . .log per cent. 



Breadth of carapace before exu- 

 viation 6 7 V inches. 



Breadth of carapace after exu- 

 viation 7-nr „ 



Increase of breadth .... L/jf „ 



Bate of increase of breadth . . 18 per cent. 



N.B. — In measuring Crustacea, it is usual to give 

 the term " length " of carapace, from the insertion 

 of the fifth pair of legs to the front margin of the 

 shell, and the " breadth " to the measurement at 

 right angles to that. Hence, with some forms, as, 

 e.g., Cancer pagurus and Xantho florida, the breadth 

 is greater than the length; while in others, for 

 example Maia squinado and Lithodes Maia, the 

 length is greater than the breadth. — W. Alford 

 Lloyd. 



Winking Marybuds.— R, S. is no doubt right. 

 The Marsh Marygold {Caltha palustris) is the 

 "Marybuds" of Shakespeare. In this neighbour- 

 hood they are called Mare-blobs, which some think 

 to be a corruption of Mere-blobs, because they 

 grow in the water ; but which is just as likely to be 

 an altered form of Marybuds. — F. T. M., Lough- 

 bo rough. 



