288 NOTES ON NATURAL HISTORY BOOKS. 



insects (Spiders are not of this class) known to spin one for theirs 

 are the Hydrophili, a species of Water Beetles. — See Introduction 

 to Entomology, in., 72. 



Cleanliness op Spiders and Insects. — tc On coming down 

 the Maine," says Mr. Rennie, " by the steam-boat from Frankfort, 

 in Aug., 1829, we observed the geometric net of a conic Spider 

 (Epeira conica) on the frame- work of the deck, and as it was co- 

 vered with flakes of soot from the smoke of the engine, we were 

 surprised to see a Spider at work on it ; for, in order to be useful, 

 this sort of net must be clean. Upon observing it a little closely, 

 however, we perceived that she was not constructing a net, but 

 dressing up an old one ; though not, we must think, to save trou- 

 ble, so much as an expenditure of material. Some of the lines she 

 dexterously stripped of the flakes of soot adhering to them ; but in 

 the greater number, finding that she could not get them sufficiently 

 clean, she broke them quite off, bundled them up, and tossed them 

 over. We counted five of these packets of rubbish which she thus 

 threw away, though there must have been many more, as it was 

 some time before we discovered the manoeuvre, the packets being so 

 small as not to be readily perceived, except when placed between 

 the eye and the light. When she had cleared off all the sooted 

 lines, she began to replace them in the usual way." 



In the Entomological Magazine, iii., p. 337, a writer states that 

 he has often observed Flies, when covered with pollen, busy them- 

 selves in scraping it off, and then roll it up into a pellet with the 

 fore-legs, and throw it away with a sort of jerk. 



Galls produced by Insects, p. 370. — At the Breslau meet- 

 ing of the German Naturalists, Sept. 1833, Dr. Hammerschmidt 

 made some observations on the galls produced on plants by insects, 

 with an attempt at their classification, illustrated by figures of not 

 less than 250 different specimens of galls and the insects producing 

 them. Mr. Westwood exhibited at the Entomological Society's 

 meeting, March J, 1836, specimens of Poppy-heads, destroyed by 

 the attacks of a small Cynipideous insect. 



J. H. F. 



Southrvark, Oct. 20, 1836. 



( To be continued. ) 



[Our Correspondent's notes on Itennie's popular compilations, are interest- 

 ing and useful ; though they contain some facts and opinions to which we 

 cannot ourselves subscribe. — Ens.] 



