I n i i;oi>r< i n >\. \in 



( )!' what further benefit they may be to mankind it would be 

 rash to predict, but it i- within the bounds of probability, that the 

 microscopic study <>(' the fresh-water varieties, it" pursued hereafter 

 as ardently as during the |>a-t few years, will result in a considerable 

 modification of our ideas concerning the generation and growth of 

 certain life-germs. 



For the behoof of the uninitiated, a Rbm words may here not be 

 out of place, <>n 



BOM PO FIND, ll'w W> COLLECT, kND ll"U TO PRESERVE 



Fresh-water Algce. \- a large majority of them, especially the 

 Desmids, are free-floating plants, it would !>< a waste of time t<> 



seek them in rapid waters; they affect | Is, sluggish streams and 



ponds ; the latter afford the most satisfactory results t" the explorer, 

 w 1 1< mi the pond is a mile or more in length and is fed by one or two 

 ks; the indentations on the margins of such a pond and its 

 tributaries, usual h abound in water grasses and mosses which 

 shelter and support the floating Alg 



The outfit need not consist of more than a nest of four or five 

 tin cans (tomato or fruit) one within the other for convenience 

 carriage; ten or a dozen wide-mouthed vials, and a small ring-net 

 of fine muslin at the end of a rod about four feet in length. 

 should a boat be needed it can usually be hired on the spot. 

 After selecting what seems to be a good locality, drag the nel a 

 few feet among the grass* - and mosses, alx>ve indicated, allow the 

 bulk of the water to drain through the muslin, and then empty the 

 residue into one of the cans ; repeal this process as often as may be 

 desirable. Ten or fifteen minutes after the cans have been filled, 

 most of the surface water may be poured off, and the remainder 

 transferred to a glass vial, where the -olid contents will gradually 

 sink, and the superfluous water can be again poured off, and the 

 Vi ssel filled up with deposits from other vials. In shallow places, 

 what is known as swamp-moss (&phagnum) f bladderwort il'iricu- 

 laria), Water-milfoil (MyriopkyUum) or other finely cut-leaf water 

 plant- are likely to abound, these should be lifted in the hand and 

 the water drained, or squeezed from them into a tin can to be 

 subsequently treated as already stated. A few drops of carbolic 

 acid in each vial, just enough to make it- presence perceptible, will 

 preserve the contents tor month- ami even year- from deterioration; 

 the green coloring matter {Chtorophyl) may fade, lut this in the 



