HARDWICKE'S SCIENCE-GOSSIP. 



143 



compound of pumice-stone built up with Portland 

 cement occupies the two back corners extending 

 partly across the back and two sides. It is always 

 necessary, when using cements, to take care that the 

 poisonous matter contained in them is extracted by 

 soaking the cemented things for several weeks. 

 After I had built up the rock-work I allowed it to 

 lie in water exposed to the full glare of the sun for 

 probably ten or twelve weeks. The last two or three 

 weeks I did not change the water, and by the time I 

 was ready to use it, a green vegetable growth covered 

 almost the whole of it — ^just the thing required. I 

 then placed it in position in the aquarium, with river 

 sand and pebbles about an inch thick and sloping 

 from the back. I then filled gently with water 

 supplied by the water company, and after standing 

 thus in ffont of the window with an eastern aspect 

 for perhaps two or three weeks, I put in two small 

 gold fish about four inches long and a small stickle- 

 back, and there they have remained ever since, and 

 are as lively and apparently as healthy as when at 

 large in the river. On the inside of the back glass, 

 a deep green vegetation has grown, and it now begins 

 to hang in some places like curtains of green down, 

 imparting a very pleasing appearance and serving to 

 make it a more natural home. There need be no fear 

 whatever in not changing the water, if only the green 

 vegetation be allowed to grow upon the rock-v/ork, 

 the two sides and the back, keeping the front glass 

 clean for viewing the interior. It will shortly appear 

 dulling the glass and becoming thicker week after 

 week. The fish are fed twice a week with bread, 

 very sparingly, and once a week I treat them to a few 

 worms obtained from a heap of chicken's dung which 

 we keep for garden use. I have no snails to serve as 

 scavengers, for, although serviceable in some respects, 

 they would entirely defeat the end for which I 

 estabUshed my aquarium, by eating off the glass and 

 the rock-work vegetation which is here used instead 

 of water-plants. Besides, they are great destroyers of 

 plant life, and as we can do without the snail and 

 the plants, we have thus more room for the fish to 

 move about in. Mr. Easton would do well to consult 

 the little works on the aquarium by Mr. Taylor, the 

 editor of SciENCE-GossiP, or by Shirley Hibberd, 

 both of them being very simple and accurate in their 

 instructions. — Walter T. Cooper. 



Strange Habit of a Bullfinch.— I have' a 

 bullfinch which is kept in an aviary, with several 

 other birds. I have noticed that he has a habit of 

 filling his large lower mandible with millet-seed ; 

 and then, retiring to a secluded corner of the cage, 

 he cracks and eats it at his leisure. Has this 

 monkey -like habit been observed before? — H. 

 B.R. 



NOTICES TO CORRESPONDENTS. 



To CORRKSPONDEKTS AND EXCHANGERS. — As WC nOW 



publish SciBNCK-GossiP earlier than heretofore, we cannot 

 possibly insert in the following number any communications 

 which reach us later than the 8th of the previous month. 



To Anonymous Querists. — We receive so many queries 

 which do not bear the writers' names that we are forced to 

 adhere to our rule of not noticing them. 



To Dealers and others.— We are always glad to treat 

 dealers in natural history objects on the same fair and general 

 ground as amateurs, in so far as the " exchanges " offered are fair 

 exchanges. But it is evident that, when their offers are simply 

 disguised advertisements, for the purpose of evading the cost of 

 advertising, an advantage is taken oi owx gratuitous insertion of 

 "exchanges" which cannot be tolerated. 



We request that all exchanges may be signed with name (or 

 nitials) and full address at the end. 



H. Daw. — Baird's beautifully-illustrated work on "British 

 Entomostraca " is the chief book on the subject. You may get 

 a copy through some second-hand scientific bookseller, such as 

 Wesley or Collins. 



B. M. Watkins. — Thanks for the teratological specimen of 

 the commondaisy. It is due to what Dr. Mastin calls "fascia- 

 tion," or fusion in growth of the stems. 



J. J. A. — The common leech js carnivorous, and preys on 

 aquatic larvae, fish, and frogs. 



J. Hodge.— Your specimen is the crumb-of-bread sponge 

 [Halichondria panicea). 



C. D.— Rye's " British Beetles " is by far the best of all our 

 less expensive books. 



S. S.— Brewer's (not Blewer's) "Guide to the Flora of 

 Surrey" is published by Mr. J. Van Voorst, i Paternoster 

 Row. 



E. F. B. — ^The following are good books for your purpose : — 

 Staveley's " British Insects," Wood's " Insects at Home," and 

 Curtis' " Entomology " for general entomology, and the Cata- 

 logues of the British Museum on the orders of insects other 

 than Lepidoptera and Coleoptera. 



W. W. W. — You will obtain all particulars concerning the 

 zoological station at Naples by applying to the director. Dr. 

 Dohrn. You would meet several English students there. 



H. Allingham. — Chenu's " Conchology " (in French, 2 vols.) 

 is crowded with plates, both coloured and plain. You may get 

 a copy through some second-hand bookseller for about 30J. 

 Wood's " Index Testaceologicus " contains about 2800 figures, 

 and may be had for about ^t,. These are the cheapest we 

 know, apart from the smaller manuals. 



D. F. — One of the British Museum publications is a " Cata- 

 logue of Myriapoda." Mr. C. F. George's valuable papers 

 on "British Freshwater Mites" have appeared in Scisnce- 

 GossiP as follows: September and December, 1882; January, 

 Fe'oruary, April, and August, 1883 ; besides those of the current 

 year. 



H. C. Craven. — Rimmer's work on " British Land and 

 Freshwater Shells " is the best we know. Tate's "Land and 

 Freshwater Molluscs " may be had for about ss. 



S. B. — You may get Mr. Brooks' pamphlet, "Notes on my 

 Aquarium," by addressing the author at Fernbrook, Hudders- 

 field. Consult Taylor's " Aquarium : its Principles, Structure, 

 and Management," published by Messrs. W. H. Allen & Co., 

 price 4^. fid. 



W. MouLTON. — Accept our best thanks for the two capital 

 photographs taken with the microscope direct from natural 

 objects. 



W. T. Haydon. — Accept our best thanks for the specimen 

 of Lathraa squamaria, which fully bears out your opinion. 



F. C. (Barnett).— ^It is a moss, Hypmivi abietinum. 



J. N. H. S. — You will find all the information you need 

 regarding the "ginger beer" plant, in Berkeley's " Crypto- 

 gamia ;" we should imagine it to be the Torula. 



C. K. F. (Preston). — The specimen you forward contains a 

 large amount of xylem, so it can scarcely be what you imagine ; 

 it must be a part of the trunk in a state of decay. If you make 

 a thin section with a razor, and mount in balsam, you will find 

 it makes a pretty microscopic object. 



H. D. G. (Croydon). — Many of the Agarics have a close re- 

 semblance, hence it is difficult to tell the species from a drawing 

 only. Could you send the actual specimen, then we should 

 indeed be happy to aid you in its identification. 



W. G. W. (Brighton). — The one on the anemone is the 

 Puccitiia anonotics, which was many years ago, in Ray's time, 

 mistaken for the sori of a fern. The other on the pilewort leaf 

 is a rust, Uromyces ficaricn. 



J. Y. (South Park Hill, Croydon). — The nurseryman must 

 have made some mistake, for. the one with small leaves is the 

 Kalmia latifolia, an Ericaceous plant, the other is certainly 

 spurge laurel [Daphne laureola, Linn.). It is very curious and 

 strange, and is worth watching as a freak of nature. Many 

 thanks for the information and the trouble you have taken. 



EXCHANGES. 



SPLENDiDLY-preserved and correctly-named Swiss Alpine 

 plants. Price dd. each. — Address, Dr. B., care of Editor of 

 Science-Gossip, 214 Piccadilly. 



Wanted, 'botanical press, to take ordinary sized sheets ; 

 must be in perfectly good order. State size, price or exchange, 

 to W. G. WooUcombe, The College, Brighton. 



Eleven vols, of Science-Gossip, 1873-83; fourteen vols, of 

 "English Mechanic," 14-27, unbound. Wanted, micro objective 

 or other accessories. — W. E. Harper, Norfolk Road, Maiden- 

 head. 



Dawson's " Chain of Life," Bentley's "Botany," Attfield's 

 " Chemistry," "Knowledge," 1884. What offers?— E. Kerup 

 Bowden Lane, Market Harborough. 



