Nov. 1, 1865.] 



SCIENCE-GOSSIP, 



247 



Collectors thus employed, are generally objects of 

 great interest on the part of bakers' and butchers' 

 boys running their masters' errands, and of the 

 public at large, if the weather permits them so to 

 be. In the present instance, as I stood over a pond, 

 occasionally making a dive with the water-net at 

 something which rose for an instant to the surface, 

 these parties stopped. One was heard to say in an 

 undertone to another who had been looking on for 

 some time, " What is that cove catching ? " The 

 reply was, " Don't know, — think it's tiddlers. O ! 

 there ! he's got something ; come and see." Then 

 they came closer, looked into the bottles, and made 

 sundry comments to one another on what they saw. 

 Occasionally their comments were diverting, but 

 more frequently otherwise. 



Perplexed whether to box ears all round, or to 

 wait till the rain should tire out their inquisitiveness, 

 it was a relief to notice that two individuals equipped 

 with rods and lines, evidently thinking this a good 

 place for their sport, stopped short in their walk, 

 and got out their tackle and commenced operations. 



Now, it was more than probable that the only 

 representatives of the finny race in that piece of water 

 — seeing that it was only a horsepond — were stickle- 

 backs, or, as the boys said, " tiddlers :" consequently, 

 the prospect of " good sport " was not great. Never- 

 theless, the anglers perseveringly plied their vocation 

 for a good hour, not even getting one of the above- 

 named fishes during the time. Perhaps I should not 

 tell this much of theii- exploits, because I felt under 

 obligation to them, since their arrival had diverted 

 attention away from my proceedmgs. 



To be pestered by small boys, inquisitive old 

 ladies, or practical jokers, is the inevitable fate of 

 the collector. His bottles and apparatus invest his 

 proceedings with mystery, or furnish materials for 

 ridicule. It is not very gratifying, for instance, when 

 you are busy in some field by a roadside, getting 

 specimens out of a pond, to hear the alarm given, 

 " Stop him ; he's going to drown himself," and find 

 that you are the individual referred to. " Vox 

 populi, vox diaboli" you mentally ejaculate; but 

 you settle down, and, like John Bunyan, grin and 

 bear it. 



Plenty of whirligig beetles {Gyrinm natator) were 

 obtained from the surface of the river Haveusboume, 

 which runs through a field close by the Shortlands 

 Station. A slide containing a good specimen of each 

 of the three pairs of legs of this water beetle, com- 

 mon almost everywhere, is well worth the trouble of 

 preparation. They must be mounted in balsam, and 

 form a beautiful object for either transmitted or 

 polarised light. 



In a horsepond just out of the town of Bromley, 

 on the left-hand side of the road going towards 

 Kes^on, were caught nine Dytiscus larvae — three full- 

 grown, and six small. Experience having shown 

 that these larvae are anything but friendly-disposed 



towards each other, they were severally wrapped in 

 grass, and taken home in this condition. 



The ferocity of these tyrants of fish-ponds is quite 

 equal to their powers. Once I kept one in a basm 

 of water for a fortnight, during which time he ate 

 seven or eight tadpoles, besides sundry earthworms, 

 and grew so large that he cast his skin twice. If a 

 small stick were presented to him, he would grasp 

 the end boldly; that mode of testing his braveiy 

 being deemed more prudent than offering him a 

 finger, which, judging by his manner of despatching 

 tadpoles, might have been painfully made acquainted 

 with the sharp pomts of his mandibles. One gripe 

 was sufiicient to settle any tadpole, and was always 

 taken through the sides, apparently quite transfixuig 

 the poor little wretch, which quivered while hfe 

 lasted, its enemy meanwhile keeping tight hold and 

 sucking its juices, till nothing but the blanched skm 

 was left to tell the tale. 



Earthworms were more trouble to him, since, 

 owing to their violent struggles, he was obliged to 

 divide the larger ones and eat them piecemeal. 



Perhaps the most interesting part in the structure 

 of the larva of Dytiscus is the tracheae. Tracheal 

 tubes of insects at all times are beautiful mi- 

 croscopic preparations, and those to be obtained 

 from this ferocious creature are among the finest. 

 A careful incision with the fine scissors down the 

 centre of the back, and repeated washing, after a 

 prolonged soaking in acetic acid, enables one to 

 remove them from the skin of the insect almost 

 entire, provided the hand be light and a sufficient 

 amount of patience be used. 



Fig. 1 . Larva of Ephemera, 



b. Natural size. 

 Fig. 2. Larva of Dytiscus. 



The only implements employed by the writer are, 

 the scissors to cut the skin open, the forceps to 

 detach the tracheae which lie along each side, and a 

 camel's-hau- brush for washing and occasionally 

 assisting the forceps. Of course, the insect must be 



