HA R D WICKE'S S CIENCE- G O SSI P. 



143 



Tadpoles. — I shall be much obliged to any one 

 who will tell me the best way of keeping and feeding 

 tadpoles. — The Needles, Strangfoni, Downpatrick. 



Mistletoe on Lime-tree. — It may interest 

 readers of this journal to know that in the grounds 

 of Clare College, Cambridge, there is a lime-tree 

 (Tilia Eiovpaa) bearing a large bunch of mistletoe in 

 a flourishing state of growth. It seemed such an 

 extraordinary occurrence that when I first saw it 

 I could hardly believe that the bunch was really 

 mistletoe : a further examination, however, convinced 

 me (though I could not climb to observe it closely) 

 that it was nothing else, the characteristic habit of 

 the plant, and the dichotomous branching of the 

 stems and leaves being very conspicuous. — Frank y. 

 Allen, St. John's College, Cambridge. 



The Sun. — " Pater " asks an explanation of the 

 phenomenon witnessed after looking at the sun — viz., 

 the appearance before the eye of " small black balls." 

 These are no doubt attributable to the fact that the 

 intense light of the sun so fatigues the nerves of the 

 part of the eye upon which it falls that the feebler 

 diffused light of the sky is unable for a time to stimu- 

 late them to action ; and we have thus a small round 

 temporary blind spot of the size of that part of the eye 

 affected by the sun. As the parts of the eye all round 

 are sensible to light, this looks like a "small black 

 ball," or rather, circular disc. If there be more than 

 one such disc, they are doubtless caused by the slight 

 involuntary movements of the eye while looking at 

 the sun, and the consequent formation of several 

 such blind spots. Other very interesting cognate 

 effects are produced by gazing steadily at highly illu- 

 minated coloured bodies. On removing the eye and 

 fixing it upon a white surface, it will be found strongly 

 tinged by the complementary colour to the one pre- 

 viously looked at. This is due to the fatiguing of the 

 nerves that respond to waves producing this colour, 

 while those not so affected respond freely to the 

 stimulus of waves of light, giving rise to other 

 colours ; hence we get a tint complementary to the 

 original. "Pater" should read Hehnholtz " On the 

 Recent Progress of the Theory of Vision," one of his 

 " Popular Lectures on Scientific Subjects," where he 

 would find much highly-interesting and curious infor- 

 mation on this subject. — John Ilcpworth, N'ew 

 Brompton. 



Sparrow-hawk and Crow. — The propensity of 

 crows to chase the sparrow-hawk, referred to at pages 

 21 and 44, is so well known in Germany as to be 

 utilized for sporting purposes. A common mode of 

 shooting crows there is as follows : A hut in the 

 shape of an Indian's wigwam, capable of holding 

 several persons, with holes in the sides about a foot 

 square, is erected in the field. Outside this hut is a 

 perch ; near the perch, opposite the hole in the side 

 of the hut, is a naked or dead tree. When the 

 sportsmen want to shoot crows, they chain a sparrow- 

 hawk, kept for the purpose, on to the perch and 

 ensconce themselves in the hut. Immediately, crows 

 arrive in numbers for the sole purpose of flying and 

 pecking at the helpless hawk and bullying it 

 generally. They settle on the dead tree to rest from 

 their labours and recruit for a renewed attack, and 

 are then a capital mark for the inmates of the hut. 

 My single experience in one of these "crow huts," as 

 they are called, enables me to answer a question as to 

 the Hoopoe at page 22, unless indeed that question 

 refers to England only. While in the hut, a bird 

 settled on the tree which I did not at the moment 

 recognize. On applying to the gamekeeper with us 



in the hut, he said " It is a hoopoe, shoot it by all 

 means : they are troublesome birds and do great 

 damage to the crops." I acted accordingly. This 

 was in North Prussia, not far from Stettin, con- 

 siderably further north than Birmingham, and in a 

 much colder climate. It was in the early spring. — 

 T. C. R. 



Destruction of Rare Animals. — Mr. H. 

 Budge, who makes some judicious remarks on this 

 subject (Science-Gossip, April, 1877), will be glad 

 to learn that the evil has long since been reprobated 

 by the East Kent Natural History Society. The 

 committee, in their last report, state that, " instead 

 of favouring the destruction of rare animals and 

 plants, by offering premiums for the best collections, 

 like the rewards of our forefathers for wolves' heads, 

 it would be better to encourage the diligence of young 

 persons by inducing them to study the nature and 

 economy of common plants and animals." The 

 committee add that, for this purpose, there are such 

 plants as our familiar willows and sedges, of which 

 the specific characters are still obscure ; and that 

 raphides and other plant-crystals, and the intimate 

 structure of the glands, hairs, and other appendages, 

 which have been often illustrated in Science-Gossip, 

 would afford ample ground for the exercise of 

 observation and proof of knowledge. And as to 

 animals, the structure and general economy of 

 numberless common species, of different classes and 

 orders, would include far more useful and interesting 

 results than the extirpation of the pi^ecious species of 

 our native flora or fauna. — E. R. 



Names of Animals. — The rabbit- catchers here 

 call the male ferret a Hob, the female a Jill. Both 

 are old names for male and female bipeds, not re- 

 spectable ; in fact, sometimes worse than not respect- 

 able — unearthly. We have Hob's-hurst-hole, the 

 cavern of the fiend's grove — even to this day avoided 

 by the superstitious as haunted; and so with regard 

 to the word "Jill."— 7?. G., Stoke-on-Trent. 



Fruit Culture. — If apples or pears are raised 

 from seed, and the suckers of such seedlings planted 

 and taken care of, will the fruit of such suckers be 

 identical with the fruit of the seedlings from which 

 the suckers were originally obtained or not ? Again, 

 if the suckers of those suckers were taken care of, 

 would the fruit so obtained be the same with the 

 suckers of the first generation ? — Boats. 



Sussex Oaks. — The history of ancient trees is of 

 great interest ; can any correspondent furnish me with 

 such, as to any Sussex Oak antecedent to the 17th 

 century? — F. PL Arnold, LL.B. 



BOOKS, &c., RECEIVED. 



"Smithsonian Report for 1875." 



" Somerville's Physical Sciences." loth edition. Edited by 

 A. B. Buckley. London : John Murray. 



" Somerville's Physical Geography." 7th edition. London: 

 John Murray. 



" The Winds and their Story of the World." By W. L. 

 Jordan. London : Hardwicke & Bogue. 



" Mesmerism, Spiritualism, &c." By Dr. Carpenter. Lon- 

 don : Longmans & Co. 



" Elementary Te,xt Book of Physics." By Professor Everett. 

 London : Blackie & Sons. 



"Monthly Microscopical Journal." Maj'. 



" Journal of Forestry." No. i. „ 



" Journal of Applied Sciences." ,, * 



" Land and Water." ,, 



" Chambers's Journal." ,, 



" Canadian Entomologist." April. 



" American Naturalist." ,, 



" American Journal of Microscopy ,, 



" Potter's American Journal." ,, 



&c. &c. &c. 



