Vm I'RKSIDKXT S ADDKESS. 



lbuv-i)i"on,<>o(l ]i()()k, made of soft copper wire, about as thick as 

 a straw (or " No. 1). IJ.W.G."), cast together by means of lead 

 or soft solder, with a. few inches of brass chain attached, 

 weighing about eiglit ounces altogether. 



Then a plaited flaxen or cotton line, which will not gnarl 

 when wet, of fifty or sixty yards in length, and sutticiently 

 strong to stand a considerable pull, enough even to straighten 

 the soft hoolv, and so set it free should it meet with wood or any 

 Imrd substance in the water which renders it fast. 



A little practice with this apparatus will enable one with a 

 fairly strong arm to throw, or rather shng, it out and gather 

 aquatic plants from a large area, fifty or sixty yards even from 

 any favourable spot for " paying "' out the line, wheie it will 

 meet with no obstacles when running out. 



Then a long test-tube, and one or two pipettes, a pair of 

 long forceps, a fiat trough, and a "condenser," or contrivance of 

 some kind for filtering out the captures, complete the contents 

 of my case under ordinary circumstances. 



How much ini])ortance 1 attach to the use of proper 

 apparatus may be gathered from the fact that I attribute the 

 non-discovery of Leptodora before 187'.>, not to its non-exist- 

 ence in our locality, but to the want of a suitable net properly 

 used, these creatures escaping through a net too rough, and 

 being unnoticeable, owing to their extreme delicacy on the one 

 hand, and the (piantity of alga they are usually taken with 

 on the other, when a net too fine in tlie mesh is used. 



It is quite true tliat tlie first one I obtained from Olton 

 reservoir was taken by dipping an inverted bottle to a consider- 

 able depth, and then by a quick turn allowing the Avater to rush 

 in ; but I have often repeated the experiment where these 

 creatures are fairly abundant, and have usually failed to capture 

 a single individual, when a few sweeps with a suitable net Avould 

 make a good gathering. 



Then, as to choice of localities. As you know, water only 

 needs to be exposed to the air, with the addition, perhaps, of a 



