TJie Animalcules in Water. 107 



many accurate and beautiful illustrations which can 

 now be obtained of all the remarkable kinds which I 

 have seen, and of many which I have not hitherto ob- 

 served. Mr. Slack's work, " Marvels of Pond-Life," 

 figures the animalcules with much spirit and accuracy, 

 aided by descriptions alike faithful and graphic. But, 

 more than this though the book is small, and the 

 style anecdotal, the subject is fully treated in its various 

 bearings, with all the lights obtainable from contem- 

 poraneous research. A microscopic student, anxious 

 for pleasantly-given information about the animalcules, 

 can hardly do without Mr. Slack's book. 



And this being the case, I shall give but a short 

 account of them here, merely indicating their principal 

 classes, and the methods of obtaining them, which I 

 have found successful. To tell the story of my pond ex- 

 perience in the spring and summer of the present year, 

 will be as good a way as any for introducing the subject. 



I was particularly anxious last March to obtain 

 some young tadpoles, during the few weeks in which 

 specimens could be had, showing the circulation in 

 the "branchiae," or external gills, an object which 

 I had carefully watched and figured several years ago. 

 I had observed a promising supply of frog-spawn in a 

 kind of pond, at a few hundred yards' distance from 

 one of the large peat-bogs so characteristic of this 

 country ; and I sallied forth to secure a small quantity 

 of it, and at the same time to fetch some water likely 

 to contain animalcules.* My implements were a 



* The locality was in the King's County, a few miles from the 

 village of Clara, 



