vi Introduction. 



The ponds referred to are all either close to, or within a 

 moderate distance of, London ;• but similar objects will in 

 all probability be obtained from any ponds similarly 

 situated, and the descriptions and directions given for the 

 capture of the minute prey will be found generally applic- 

 able. Care has been taken throughout to explain the most 

 convenient methods of examining the objects, and although 

 verbal descriptions are poor substitutes for the teachings of 

 experience, it is hoped that those here given will remove 

 some difficulties from a pursuit that no intelligent person 

 can enter upon without pleasure, or consent to abandon 

 when its elementary difficulties have been mastered, and 

 the boundless fields of discovery are opened to view. Let 

 not the novice be startled at the word " discovery." It is 

 true that few are likely to arrive at new principles or facts 

 which will inscribe their names upon the roll of fame ; but 

 no one of ordinary powers can look at living objects with 

 any considerable perseverance, without seeing much that 

 has never been recorded, and which is nevertheless worthy 

 of note; and when the mind, by its own exertions, first 

 arrives at a knowledge of new truth, an emotion is felt 

 akin to that which more than recompenses the profoundest 

 philosopher for all his toil. 



* Many are now (1871) destroyed by the progress of building. 



