r.v a. mi: \i> BDWABD8. 1 i 



been remarked, the finer filamentous Bpeciee of water plants 

 yield the best results; the marine faeoids, as the "bladder 



wrack," and simihir species, secrete a mucus which m ems to be 

 repugnant to the growth of most diatoms; yet upon the stalks 

 o( Laminaria, and some other large olive-colored algje, are found 

 the finer red-tinted species, which are themselves beautiful ob- 

 jects of study, and are, in turn, the homes of hosts of minute 

 forms of life. Water plants, marine or fresh water, should not 

 be cleaned in any way, but merely raised from the water, and, 

 after draining for a short time, be either laid upon a piece of 

 clean paper to dry, or hung up where the air and sun can 

 rapidly evaporate the moisture. Marine plants will usually not 

 dry thoroughly, as the salts present in the water absorb 

 moisture from the air; hence they are liable to mould unless 

 they are packed in paper. The moss-like carpeting seen upon 

 submerged rocks is often made up of beautiful specimens of the 

 filamentous species of diatoms alone, and it will be well to 

 scrape the surface of the stone, and, placing the mass in a 

 bottle, cover it with alcohol, which will become colored from 

 dissolving the coloring matter of the diatoms, and preserve 

 them in the very best manner for future study. Fresh water 

 forms are very often found hanging in green -colored festoons 

 from the exit pipe of drains, sluices, or fountains,, and may he 

 preserved in the same way. 



The green, brown, or fawn-colored scum, which floats upon 

 the surface of the water of roadside pools, ponds, bogs, 

 marshes, or rivers, consists usually of little else but diatoms, 

 and may be taken up by means of a spoon or bottle, and then 

 preserved in alcohol or dried upon paper. The surface of the 

 sea may be skimmed by means of a net of tine muslin, haying 

 an opening left in the bottom, in which a four or six ounce 

 wide-mouthed phial is tied, and towed at the stern of a vessel. 

 If the sea water be strained through Mich a net, either by tow- 

 ing behind a boat, or even poured from a pail, the solid matter 

 contained in it will be washed down and gradually collect in 



the phial, which can then he removed and tightly corked, and 

 another substituted. Some wry beautiful forms have been 



procured in this way. The stain occasionally seen on the sur- 

 face of the sea in some latitudes, as well as the minute organ- 



