SCIENCE-GOSSIP. 



109 



Waterproof Cement. — I should be glad if any 

 of your readers could tell me of a recipe for making 

 a waterproof glue or cement. One soluble in dilute 

 acids preferred. — Alfred J. Johnson, Birmingham; 

 August yth, 1896. 



Cuckoo's Egg in Pied Flycatcher's Nest. — 

 A friend informs me he has recently seen the nest 

 of the pied flycatcher with three eggs, amongst 

 which was a cuckoo's egg. The extreme rarity of 

 the former bird makes this a very interesting fact. 

 — E. Wheeler, Clifton; June 18th, 1896. 



Death's-head Moth Caterpillars Abundant. 

 — Have any of your readers observed an unusual 

 number of the larvas of the death's-head hawk 

 moth (Acherontia atropos) this year? It is no un- 

 common thing for two or three to be brought to 

 me, but this year I have had fifteen, of which 

 twelve were found in a small cottage garden, not 

 a quarter of an acre in extent, and close to my own 

 garden. The others were found in three different 

 places at no great distance from here. Once I had 

 thirteen in the course of one late summer, but 

 never before so many as this year. Once only 

 have I found a specimen of the perfect insect in 

 my garden, but it was much worn and not worth 

 preserving. — [Rev.] H. M . Mapleton, Badgnorth 

 Rectory, Somerset ; August ijth, 1896. 



Food of Plusia Moneta. — With reference to 

 Mr. C. A. Briggs' note and query (ante p. 81) on 

 Plusia moneta and its food plant ; the fact that the 

 larvae of this new acquisition to our fauna will feed 

 upon the ordinary garden larkspur (Delphinium), a 

 plant very closly allied to monkshood (A conitum), is 

 perhaps not generally known. Monkshood is such 

 a particularly all-round poisonous plant that it is to 

 be found freely only in old-fashioned country gardens, 

 so that when my larvae this spring had eaten up the 

 supply of monkshood taken at the time they were 

 captured, they had to eat larkspur, of which I had 

 a plentiful supply, or die. I found they took to it 

 readily enough, and fed up easily and freely. Whilst, 

 however, the larvae that fed up chiefly on the monks- 

 hood pupated in a bright orange- coloured cocoon, 

 those that for the most part ate larkspur made a 

 dirty white cocoon. Possibly this difference may 

 not be entirely due to the food-plant, but it appears 

 probably so, to a large extent. — Thos. Wm. Hall, 

 Stanhope, The Crescent, Croydon. 



Effect of Fear on Birds. — The article in 

 SciENCE-GossiP (ante p. 34) on the effect of fear 

 upon herons, has recalled to my mind a similar 

 incident with regard to swallows. A few years ago, 

 at Cawthorne, in Yorkshire, I was playing with 

 a youngster's iron hoop and sent the thing flying 

 down a steep hill. The road took a sharp bend at 

 the bottom of the hill, with the result that the hoop 

 went with a loud noise against the stone wall. 

 Two swallows were flying over the road at the 

 time, and as the hoop struck the wall beneath 

 them they dropped as if they had been shot. They 

 fell into a bed of nettles, and though I was quite 

 thirty yards away I found on walking up to the 



nettles they were still lying there, as though 

 stunned. I picked up one of them in my hand, 

 whilst the other flew away. The one I secured 

 seemed in a dazed condition, and sat in my open 

 hand for at least three minutes, when I threw it up 

 in the air, rather expecting it to drop, but it flew 

 away easily as it was uninjured in any way. I 

 have never since seen a similar case, and was 

 much interested in your correspondent's note. — 

 Thos. Midgley, Chadnnck Museum, Bolton. 



Cleaning Hard-Set Eggs. — Having for years 

 experienced great difficulty in dealing with birds'- 

 eggs which I have taken hard-set, I have this year 

 tried the following method which I have found 

 most satisfactory, and which I think might prove 

 useful to other collectors. Take a fine needle and 

 prick a circle on the side of the egg, making the 

 holes as near an even size and as small as possible. 

 When the piece of shell within the circle is entirely 

 separated, carefully remove it, and with a fine pin, 

 bent as a hook, extract the contents of the egg. 

 Thoroughly wash out the egg, dry it, and lightly 

 stuff it with cotton wool. Apply a little liquid 

 gum on the inner surface and edge of the removed 

 piece of shell, and replace it carefully in its previous 

 position. If this be done with extreme care and 

 nicety, the line of the circle is barely perceptible. 

 The size of the circle must be about one quarter of 

 an inch in diameter, more or less according to the 

 size of the egg. In making the holes it is best not 

 to prick them too close to one another at first, but 

 to go round a second or even a third time if 

 necessary. Also it is helpful to draw a circle 

 faintly with a pencil, and to put a cross line to 

 show the exact position of the piece of shell when 

 replacing it. I have lately prepared for my 

 collection in this manner, four eggs of grasshopper 

 warbler, one of red-legged partridge, and two of 

 coots, all of which eggs had been extremely hard 

 set, and it would have been quite impossible to 

 have blown them in the ordinary way. — E. W. 

 Du Buisson, Hereford ; August, 1S96. 



Daphnia and Rotifers. — Mr. Saml. Bolton 

 writes me as follows: "Your note on red patches in 

 small ponds has nothing to do with Daphnia or 

 Rotifers (Science-Gossip, August, 1896), but are 

 Tubifex, and most likely some of the blood-red 

 worms with them. If you had plunged a fine net 

 into the mud you would have landed thousands ; 

 you have to be quick or they withdraw under the 

 mud, they will also retract if your shadow goes 

 over them. Mr. Baird must also have been mis- 

 taken with the same thing. The Daphnia would 

 be in the water, but you could not see them ; but 

 the sun shining on the Tubifex, they would show 

 through the Entomostraca." Mr. Bolton is no 

 doubt a much more experienced naturalist than I 

 am, but he is clearly wrong in his explanation of 

 the red patches, for I filled two or three bottles 

 from the red patches and found them to consist of 

 one dense mass of Emtomostraca. The bottle of 

 water looked like red ink from the immense number 

 of its small red occupants. Professor Carr, of the 

 Nottingham University, an excellent observer, saw 

 them as well as myself, and there could be no doubt 

 in the matter. The problem I wish to have solved 

 is why the Daphnia collect in such enormous 

 numbers accompanied by parasitical rotifers ? Is 

 it for mutual protection against these parasites ? 

 I sent a retriever dog to swim through the mass, 

 and even then the Daphnia did not "retract," as 

 as Mr. Bolton says, but merely shifted their 

 position. — W. Warrand, Ormidale, Colintraive, Argyll- 

 shire ; August gth, 1896. 



