THE YOUNG NATURALIST 



191 



mouldy. I have dried some of them, and 

 tried to brush off the obnoxious fungus, but 

 have not succeeded satisfactorily. I am 

 recommended to use carbolic acid, will 

 some of your readers tell me how to pro- 

 ceed ? I am afraid the effect of this in my 

 drawers would be to destroy my specimens 

 altogether.— X.Y.Z. 



REPLIES. 



6 



The Gipsy Moth. — No general reply 

 having been given to this query, I would say 

 that it is a subject that has occupied my 

 attention for a long time, and I asked a 

 similar question some years ago in the pages 

 of " Science Gossip." To that I received 

 no reply, nor have I ever met with a collector 

 who took Dispar. It must surely be a fatal 

 name for a British insect— the Large Copper, 

 which bore the same specific name has 

 disappeared, and I am afraid the same 

 must be said of the Gipsy Moth also. A 

 few years ago I made it my business 

 to ask every one of my correspondents if 

 they knew any one who took Dispar, or if 

 they could supply me with a captured 

 specimen. Not one of them knew of a 

 recent capture, or had a captured example 

 at their disposal. I was recently told that 

 those so freely reared in this country were 

 from French eggs originally, and were what 

 might be called the continental type of the 

 insect, differing considerably from old 

 English specimens. P. rutilis, the contin- 

 ental form of the Large Copper, differs it 

 will be remembered, from the English 

 specimens. The Gipsy does not seem to 

 deteriorate by close interbreeding, and 

 sometimes breeds exceedingly true. A 

 Darlington collector bred a male with pale 

 bands, and from it, obtained large numbers 

 of the same form, which is figured in 

 Mosley's Illustrations, from a specimen in 

 my collection. Mr. Tugwell recently showed 

 me two pair, in which the hind wings had a 

 circular piece wanting at the tip. Had the 



pieces been cut out with a pair of scissors it 

 could not have been more regularly done, 

 and he informed me that the whole brood 

 of seventy or eighty specimens, all had the 

 same peculiarity. — John E. Robson, Hartle- 

 pool. 



22. 



Sudden Appearance of Plants. — Your 

 correspondent, J.G.H., asks if it is correct 

 that Sisymbrium Ivio (the London Rocket), 

 sprung up in large numbers, on the ruins of 

 London, after the great fire ; if there are 

 other similar cases ; and how they are 

 accounted for. There is no reason to dis- 

 pute the correctness of the statement about 

 S. Irio. It is not a very common plant, but 

 is chiefly found on old walls and waste 

 ground in large cities. The seeds fall into 

 cracks and crannies, where, for want of 

 light, air, or moisture, they are unable to 

 germinate, and remain dormant, perhaps, 

 for years. Something occurs to the walls — 

 they are burnt down, pulled down, or other- 

 wise disturbed ; the seeds that had not the 

 conditions necessary for germination, now 

 find them, and in a case like the great fire of 

 London, where the ruin was not only very 

 extensive, but much lay undisturbed for a 

 long time, the plants had an opportunity ot 

 showing themselves in sufficiently large 

 numbers to call general attention to the 

 circumstance. Now-a-days, when the ruins 

 of a fire are quickly removed, and new 

 buildings spring at once from the ashes of 

 the old, such an occurrence could scarcely 

 take place ; and, indeed, modern build- 

 ings, more solidly and compactly built, do 

 not so readily allow plants of any kind to grow 

 upon them. There are many similar cases 

 on record, one of the most interesting being 

 mentioned by Macauley,in the fourth volume 

 of his History of England. After the battle of 

 Landen, in 1 693 , the ground where the bodies 

 of those slain in the fight had been interred, 

 was, in the next summer, covered with 

 poppies, the seeds of which had been lying 



