36 HALF-AN-HOUR 



Daphnia pidex. The parts of the mouth are rather after the type 

 of a Crustacean than of a Dipterous Insect-larva, and some 

 amusing speculations might be indulged in as to the way whereby, 

 according to evolutionist fancies, the Insect-larva's mouth had 

 become modified towards a Crustacean tyj^e through feeding upon 

 Crustacea ! 



There are two pairs of curious floats — one pair in the anterior 

 third, the other near the tail. 



Rymer Jones found no possible way of mounting this object 

 but by putting it up in a cell with pure wate?^ alive, sealing up at 

 once with a margin of gold-size. In this way, they had been pre- 

 served by him for twelve months, " improving for some time," as he 

 says, " by keeping." 



Syritta pipiens, S' • — In glorious Westwood we read (p. 559, 

 Vol. 2) : — " The larva of Syritta {Xylota) pipiens has been found 

 in horse-dung by De Geer ; it is thicker in front than behind, with 

 a small point on the head," and in the Generic Synopsis at the 

 end of the book (p. 136) that Meigen gave it the name of Xylota. 

 There is but one species in this genus. It was called by Linnaeus 

 Alusca pipiens. Horse-dung is easily procured, interesting larvae 

 occur in it, examine them carefully in the live-box or live-trough in 

 the living state ; if you have only one or two, draw and describe 

 them carefully, then put them back again to breed out ; watch 

 them, and look for the puparium (pupa-like condition ; it is not a 

 true pupa, but the skin of the larva becomes hardened and horny), 

 draw and describe this again in difterent aspects, and put care- 

 fully back as before. Then, with a little more patient watching, 

 one day you'll see the fly ; examine, describe, draw, and if a 

 female, try to get her to lay eggs, and you have the life-history 

 nearly complete. But not quite ; for if so fortunate as to get 

 several, you may have the opportunity of witnessing the union of 

 the sexes (a very important point). The chapter may now be 

 closed. You will for some time have had a most interesting and 

 instructive study before you, and will be able to furnish a valuable 

 paper for the " Transactions " of our own Society, which I hope 

 some day to see published. 



Claws of Insects. — In Notonecta glauca we have a typical 

 illustration, and a most interesting one, of the truth that the claws 

 of all insects, whatever form they assume, are but modifications of 

 hairs ! I to adapt them to special purposes. 



Leg of Dytiscus. — Dytiscus is a great predaceous Water-beetle ; 

 the largest our country produces. To enable it to overcome the 

 struggles of its powerful partner in the slippery element, the males 

 have the three proximal joints of the anterior tarsi greatly dilated 

 and furnished with sucking discs. The present specimen shows 



