HARDWICKE'S SCIENCE-GOSSIP. 



209 



White Zinc Cement.— Take one part, by weight, 

 of mastic tears, and three parts of dammar, dissolved 

 in benzol. To three pints add i lb. pure French 

 oxide of zinc, ground in linseed oil. Stir thoroughly ; 

 also when in use. If too thick add benzol. — 

 J. R. M. S. 



Occurrence of Daphnia Bairdii and Diap- 

 TOMUS Castor. — Your readers will, I have no doubt, 

 be glad to hear that the two Entomostraca Daplinia 

 Bairdii and Diaptomus castor ha\-e been captured 

 here in considerable numbers. Some few weeks ago, 

 I got a few specimens of these interesting animals 

 from a large reserve mill-pond. Since then I have 

 procured them in great numbers, although on an 

 intermediate occasion, when the sun was shinine 

 brightly, I failed to get any. Daphnia Bairdii, or 

 Hyalodaphnia KaJdbergcnsis, as I presume it ought to 

 be called, is a beautiful animal, and one well worthy 

 of study. Mr. Forrest, the dehneator of Mr. Bolton's 

 portfolio of drawings, states that he never found a 

 female of Hyalodaphnia with more than two eggs, and 

 suggests that this may account for the fact of the 

 animal being so rarely found. I may say that the 

 first female I examined had six ova, and since then I 

 have found females with no fewer than eighteen ova, 

 so that the animal is rather prolific. AYhat is the dis- 

 tinguishing feature of the male ? Diaptomiis castor 

 very plentiful in same reservoir. Mr. Forrest's draw- 

 ing of it very faithful, as all his drawings are. By 

 the bye, my males all have that peculiar form of 

 antennre (right) which he terms abnormal. From the 

 fact of these Entomostraca having been found at places 

 so far apart as Olton reservoir (Birmingham) and 

 North-East Lancashire it is very probable that they 

 are not so rare as was at first supposed, and I hope 

 that naturalists in all parts of the country will keep a 

 sharp look-out, not only for these animals, but also for 

 other rarities, and report to yow.— Jo/in E. Lord, 

 RawteiistaU. 



A New Collecting Bottle.— In the July number 

 of the "American Microscopical Journal," a Mr. 

 C. E. Hanaman,^describes a form of collecting-bottle 

 which he has in use. It consists of an ordinary wide- 

 mouthed bottle, having a number of holes, half an 

 inch or more in diameter, bored through one-half, 

 at a distance from the bottom, corresponding to the 

 capacity of the bottles in which the collector intends 

 to bring home his material. Over the holes and 

 around the bottle is tightly laced a piece of fine 

 muslin, which should be at least three times as wide 

 as the diameter of the holes. Over the muslin, both 

 above and below the holes, a rubber is placed so as 

 to make all watertight, except at the points corre- 

 sponding to the holes. Any quantity of water may 

 be poured into the bottle, and will rapidly run out 

 through the muslin covering the holes, leaving the 

 organisms which it contained in the bottle ; together 

 with so much water as the lower part of the bottle, 



below the holes, will hold. This can be poured into 

 smaller bottles for transportation by inclining the 

 collecting bottle so as to allow its contents to 

 run out on the imperforated side. This bottle is a 

 modification of Wright's form, with the advantage 

 of doing away with the inconvenient funnels. 



American Monthly Microscopical Journal- 

 — The current numbers of the above journal contain 

 a series of valuable articles on the "Detection of 

 Adulteration in Food," by the aid of the micro- 

 scope. In the July number the special subject is Tea, 

 and we here learn the interesting fact, that to render 

 heavier the cheap and medium-priced teas they are 

 dusted when damp with a substance which can in no 

 way be distinguished from a blue clay. In specimens 

 of cheap teas were found grass stalks, pieces of the 

 stem of some pithy weed, &'c., all evidently soaked 

 in an extract of tea, and a good many fragments of a 

 blue colouring matter soluble in water. 



ZOOLOGY. 



"Animal Defences." — Under this suggestive 

 title the address of the President of the Liverpool 

 Naturalists' Field Club (the Rev. H. H. Higgins, 

 M.A.) appears in the last number of the Proceed- 

 ings. The address deals with the defences of all 

 kinds of invertebrate animals, from rhizopods to 

 insects. 



The American Association for the Advance- 

 ment of Science was held at Boston on August 17, 



The Epping Forest Naturalists' Field Club. 

 — Part IV. of vol. ii. of the Transactions of this 

 vigorous club is to hand, containing eight papers, of 

 which four are bearing on local geology, entomology, 

 &c. Professor Boulger's " Evolution of Fruits " is a 

 thoughtful and original contribution. Mr. R. Mel- 

 dola's paper, on "The Developmental characters of 

 the Larvae of the Noctuse, as determining the position 

 of that Group," will be read with great interest by 

 all philosophical entomologists. 



The Royal Society of Tasmania. — The 

 monthly notices of Proceedings of the above society 

 for 1879 are to hand, illustrated by some excellent 

 plates of fossils, &c. Among other communications 

 we have one on "The Habits of the Platypus ; " on 

 "The First Secondary Fossils found in Australia," by 

 R. Etheridge, F.G.S. ; on " New Species of Helices," 

 another contribution to our Tertiary Geology of Table 

 Cape; on "Some Tasmanian Trochidse ; " on 

 " Tasmanian Land Shells ;" " Census of the Plants 

 of Tasmania ; " Meteorological Reports, &c. 



"The Book of the Rabeit." — Part XI. the last 

 of this work, has just come to hand, published at the 

 "Bazaar" Office, 170 Strand, London, and edited by 

 Mr. Leonard W. Gill, who is well fitted to deal with 



