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HARDWICKE'S SCIENCE-GOSSIP. 



[April 1, IS68. 



NOTES AND QUERIES. 



House-plies. — Where do house-flies deposit their 

 eggs ? This has always been a mystery to me, and 

 I was more astonished than ever on hearing the 

 following from a friend. He had been, last autumn, 

 preparing some Extractum Conii, and had laid aside 

 the jar from which he had decanted the extract, 

 leaving some dregs still in. On going to it, some 

 three weeks afterwards, he found a few maggots 

 clinging to the sides of the jar by small and delicate 

 legs. These creatures were of a light brown colour, 

 with a hard integument, and their bodies were 

 divided into segments ; in fact, at first sight they 

 were like small woodlice, about a quarter of an inch 

 long. He preserved them in a bottle in the warm, 

 and shortly there came from them what appeared to 

 be ordinary house-flies. Now can any reader of 

 Science-Gossip tell me for certain what the insects 

 were and whether house-flies or not, why they should 

 have chosen such a poisonous home, unless < Conium 

 has no effect on the lower orders of animals ? — 



a h. b. 



Rearing Larvje. — Could you give me any infor- 

 mation on the management of larvae of Dasychira 

 fascelina — as I have for two years obtained a large 

 number of larvae of all sizes, but never been able to 

 rear an imago, the larvae always dying when nearly 

 full grown ?— /. 31. Hick. 



Answer. — I think the reason of Mr. Hick's 

 failure with larvae of D. fascelina is probably due to 

 one of two causes : 1. It requires change of diet, 

 especially at the age he mentions. The species is 

 very partial to dwarf fallow. 2. The food should not 

 be too juicy. The native haunts of the species are 

 generally bleak, such as exposed heaths ; and 

 species inhabiting such spots are very apt to die off 

 three-quarters grown if provided with too juicy pro- 

 vender.— H. G. K. 



Anachronisms in Science. — I have, in common 

 with most of your readers, admired the two beau- 

 tiful woodcuts given in the February number of the 

 Gossip, from Professor Blanchard's work. They 

 are fine studies of insect life, and artistic in their 

 grouping ; but while we admire all this, still, to my 

 mind, they have a great defect, that of figuring the 

 caterpillar, pupa, and imago in one picture. Now 

 pictures should represent what is seen at a glance, 

 and can legitimately only take in what can occur at 

 the same time ; and in this they should differ from 

 diagrams, one of which may lawfully represent many 

 points of sight, scales of size, and periods of growth, 

 even in the life of an individual. These different 

 modes of treatment ought to separate perspective 

 from geometrical drawing. Great painters have, 

 however, sometimes fallen into this error; Rubens 

 painted himself between his two successive wives, 

 to the amusement of his contemporaries. Imagine 

 an artist representing himself and his remote 

 ancestors in one picture, and his boyhood and man- 

 hood in another. These anachronisms in insect 

 representation I think are not more justifiable. — 

 C. 0. G. Napier, F.G.S. 



Acacias. — Acacias and Mimosas appear to be 

 peculiarly desert plants ; some species of the tribe 

 being found in almost every known desert. What 

 special properties have these plants to enable them 

 to flourish in scanty soil, and to resist drought ? — 

 C. E. I). 



Insects Growing. — Surely, both the large and 

 small flies we see in our houses, on walls and 

 windows, are all of them full-grown insects— flies 

 of different species. Insects of course grow, but 

 not after they have attained their perfect form, at 

 any rate those I have watched did not. I was first 

 led to inquire into the matter by the very passage 

 in Mr. Wood's book which " F. M. N." has quoted. 

 Has "F. M. N." ever watched a butterfly in its 

 transformations, and noticed how short a time the 

 wings are in expanding? The few seconds oc- 

 cupied in this process was once called by a juvenile 

 friend of mine "the butterfly's growing time," — we 

 were looking at a beautiful specimen that had just 

 burst its case open, and the " growth " of the wings 

 astonished him. I also think that if " F. M. N." 

 will carefully examine his small grasshoppers, he 

 will discover them to be wingless, or nearly so. 

 They only attain to the full dignity of perfect wings, 

 I imagine, when grown up, consequently Mr. Wood's 

 statement that the winged insect never grows," is 

 not our theme, because grasshoppers in the pupae 

 stage skip about. A grasshopper's transformations 

 are partial only. There is a wingless grasshopper 

 in America; it is very like a cricket in shape, and 

 hides away under stones. — H.E. Watney. 



New Zealand Greenstone. — This mineral is 

 called in China imperial jade, and is found in various 

 localities in China, Turkey, Little Thibet, the 

 Himalaya mountains, and the river Amazon. The 

 locality nearest home is Schwemmsal, near Leipzic. 

 It is found in solitary blocks in alum-shale, and is 

 often washed down by rivers. It is sometimes 

 found in large masses, and in China is an imperial 

 monopoly. Its colour varies from the palest leek 

 green, almost white, to deep sap green. It is usually 

 translucent, but sometimes nearly opaque. There is 

 a red variety less pretty, I think, than the others. 

 Jade is excessively valued in China, being bought 

 up at the sales of mandarins' effects at high prices. I 

 saw a set, a tea-pot, four tea cups, and box for sweet- 

 meats, all of pale green jade, standing upon an oval 

 dish of red jade 12 inches by 9, which had been 

 brought from the summer palace at Pekin. The 

 cups were carved with lotus and other emblems. 

 These in China were said to be worth £2,000, but 

 at Christy's sold for £250. I saw at the same time 

 a host of bowls, cups, and other utensils of jade 

 which I have not space to particularise. The locality 

 in New Zealand where the jade is found is said to 

 be a secret. I remember reading in "Thomson's 

 New Zealand " that the greenstone is not found in 

 the island at all, and is supposed by some authors 

 to have been brought by the Maories from Hai- 

 wacki, from whence they say "the seed of their 

 coming is." The Rev. J. G. Wood exhibited, 

 before the Anthropological Society, last week, a 

 curious ornament carved with foliage, exhibiting a 

 revolving wheel cut out of a solid piece. It is a 

 silicate of magnesia and lime. Its hardness has 

 been much exaggerated, being really that of felspar 

 and less so than quartz. Any practical lapidary 

 could easily cut it with emery, still more easily with 

 corundum. I mention this because some time ago 

 it was stated that nothing would cutjit but diamond- 

 dust. I am not surprised that it is undervalued 

 by European jewellers, for it has neither brightness 

 of colour nor lustre, and the commonest chalcedony 

 is prettier— C. 0. G. Napier, F.G.S. 



Dog-fleas. — Can any one tell me how to rid a 

 dog of fleas ? I have tried repeated washing in a 

 strong solution of soda without effect. — L. P. 



