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HARDWICKE'S SCIENCE-GOSSIP. 



of " ripple marks " on the surface of partially sheltered 

 snow,' during the height of the storm ; owing to the 

 fineness of the flakes they were driven so rapidly up 

 the windward side of the declivity and so filled up 

 the hollows on the leeward side equally rapidly, thus 

 causing the whole surface of "ripple marks " to move 

 onward in a most remarkable degree joining and dis- 

 connecting, and changing their whole direction upon 

 each temporary shift of the gale. — E. Lovctt, 11 oily 

 Mount, Croydon. 



NOTES AND QUERIES. 



Trap-door Spiders. — I have been watching with 

 great interest for some little time past, both here j 

 and at Mentone, the ways and habits of these in- 

 genious little creatures. A few days ago I found a 

 peculiarity in the nest of a Nenicsia Eleauora, quite : 

 new to me, and, as far as I am aware, never yet 

 noticed by any one. I was digging out a very large \ 

 wafer-door nest, which proved to be that of a Ncmesia j 

 Elcaiiora ; as I soon came upon the second door with- ; 

 out a branch, about an inch and a half or two i 

 inches below the second door, I found a very small : 

 cavity or groove (about an inch long) in the wall j 

 of the tube, separated partly from it by a silken 

 filament, and completely filled with the husks of 

 small red ants. At the bottom of the nest I found i 

 the sjaider, a very large one. There were no remains 

 of ants at the bottom of the nest, such as one often 

 finds. I cannot learn tliat such a storehouse or larder 

 has ever been observed in the nest of this spider, \ 

 and therefore feel it a duty to make the fact known. 

 Hoping that some of the readers of your journal, 

 better informed than myself on the subject, will 

 be able to enlighten me on the point in question. — 

 M. L. Fanldcr IVhite, San Rcmo. 



Mr. H. B. Sharpe on Cuckoos. — This well- 

 known ornithologist, in a lecture recently delivered 

 before the Uirmingham Midland Institute, said : 

 The ground cuckoos, unlike the tree cuckoos, built 

 their nests, but they were not very far advanced in 

 the art of nest-building. As they reared their own 

 young, and did not foist their eggs upon other birds 

 they would, if the audience liked, call them the " re- 

 spectable cuckoos." If one were asked to name the 

 principal characteristic of the common cuckoo, a 

 reply would no doubt be given, "It does not make 

 its own nest, but lays its eggs in other birds' nests." 

 Why did it do that ? Many theories had been started 

 upon that point. He believed the reason why the 

 female cuckoo never built a nest of her own was 

 because she never had the time to make one. The 

 cuckoo was what they called a polyandrous bird. 

 She had a good many husbands. The proportion of 

 males to female cuckoos had been represented as 

 twenty-five of the former to every one of the latter. 

 From his own experience he was led to think that 

 that was an exaggeration, but he believed there 

 were at least five males to every one female cuckoo 

 that visited this country. They would therefore see 

 there were four unfortunate male cuckoos wlio could 

 not find a wife, and the consequence was the female 

 bird was continually chased by every one of the 

 males, requesting her to marry them, and build a 

 nest. In America there were not so many male 

 birds in excess of the females, and the result was the 

 cuckoos in that country built their own nests. There 

 was a time when they did not know how to build 



them. The American cuckoos did not lay their eggs 

 and hatch them all at once, like some English birds 

 did, but would lay them at intervals, leaving the 

 young birds first hatched to hatch the remainder. 

 It was somewhat curious that after June or July 

 the cuckoos were seldom heard in our own country. 

 Their stay here was exceedingly short, with the 

 exception of the young birds which were hatched 

 in England. Those remained a little longer. The 

 idea that the cuckoo sucked the eggs of other birds 

 was all rubbish. When they considered that ninety- 

 two different kinds of birds were known to be selected 

 by the cuckoo as suitable foster-parents for their 

 young, they could well imagine the great many kinds 

 of nesis for the bird to choose. They could accept 

 as a fact beyond dispute tliat the hen bird laid her 

 egg upon the ground, and then picked it up and 

 carried it to the nest of the foster-parent. 



Phosphorescent Centipedes. — On the night of 

 December 8tli, I captured a phosphorescent centipede, 

 which I take to be Gcophilits sid'tcrniuctts, described 

 in " Nature," No. 579, p. 99, where the correspondent 

 says that a couple of these animals produced an effect 

 "like moonlight through the trees," and that he was 

 enabled to read a letter by the illumination. The 

 illuminating power of my specimen was about equal 

 to the effect produced on the roughened side of a 

 fusee box on which a fusee has been struck in the 

 dark. I secured the animal by the light of a lantern, 

 and he shone in my hand quite as brilliantly as he 

 did before he was disturbed. I put him in a small 

 glass tube, and watched him in the dark for some 

 time. The light extended nearly three-c[uarters of 

 an inch, or about half his length from his head back- 

 wards, and seemed to shine in two lines parallel to 

 the animal, but not quite close to it. Wishing to 

 preserve it, I filled up the tube with spirit, which 

 caused the animal to shrink somewhat, and turn a 

 darker brown. When alive, the animal was a very 

 light colour for a centipede, and a good deal narrower 

 in proportion to its length. It may not be so un- 

 common as might be supposed, escaping the general 

 notice, both from its subterranean habits, and when 

 met with in the daylight, bearing a pretty close 

 resemblance to its non-luminous brethren. — L. Adams, 

 Maidenhead. 



LiGHTNiNC. — Being very much interested in things 

 electrical, I waited with an enthusiastic impatience 

 for the replies to C. B.'s query with reference to 

 sheet lightning. Turning to all the books I could 

 lay my hands upon the subject, I could find nothing 

 very satisfactory. As stated by Mr. Woollcombe, 

 Ganot says that sheet lightning is supposed to be 

 produced in the cloud itself illuminating the whole 

 mass. In an article on Lightning in the latest edition 

 of the National Encyclopaedia, I read that when the 

 electric discharge permeates generally the surrounding 

 masses of weakly electrized vapour, the appearance 

 then is that of a sudden and wide illumination, as 

 in summer, or sheet lightning. Then we have that 

 other theory mentioned by E. Parfitt, of the flash 

 not having acted strongly enough upon our retinas 

 to produce a visible image of the fork. As these 

 theories are very conflicting, I shall be glad if any 

 of the readers of Science-Gossip can throw more 

 light on the subject, and also explain the cause of 

 globe liglitning. Guthrie says such meteors, or 

 "fireballs," which may properly be called thunder- 

 bolts, appear to avoid contact with the earth. Ganot 

 says they often rebound on reaching the ground j 

 at other times they burst and explode with a noise 

 like that of the report of many cannon. Sonije four- 



