140 The Microscope. 



press purpose of releasing them at the identical place 

 where they were captured. 



I took notes at the time of a few facts which I 

 observed, and I made some rather elaborate drawings, 

 from a small number of which Plate VIII. is taken. I 

 also noted down, and will now relate, the manner 

 which I found convenient for securing the different 

 creatures, and which I still prefer to any other 

 methods. 



The animals which are most easily obtained are 

 small fish, as sticklebacks, frogs, and (during spring 

 and a part of summer) tadpoles. 



The stickleback being, according to Mrs. Glass's 

 immortal maxim, " first caught," can be secured in 

 this way : A glass slide should be got ready, also a 

 little lump of jeweller's cotton, and a piece of soft 

 thread, about a quarter of a yard long. Then the fish 

 can be taken out of the water, and laid on the glass, 

 its head near one end, so that its tail might come near 

 the centre of the slide (No. 24, a). The cotton is to 

 be made quite wet, and laid over the fish, leaving only 

 its tail visible, and the thread, also made wet, is to be 

 wound round, b ; no fastening will be necessary. The 

 fish can move its tail a little, but will probably seldom 

 do so, and the tail-fin can be spread out, if required, 

 by a camel's-hair-brush. The use of the lump of 

 cotton is to prevent the threads from pressing the 

 fish anywhere too sharply, and also to retain as much 

 moisture as possible around the gills. Thus arranged, 

 the fish may be kept several minutes on the slide, a 

 few drops of water being occasionally spilt over it. 



