8 



EECEEATIVE SCIENCE. 



for the attachment of — 1st, a curved cutting- 

 hook, like a reaping-hook in miniature ; 2nd, 

 a small muslin net ; and 3rd, an old spoon. 

 A good Coddington lens and slip of glass, or 

 a " live-box," may help in some cases to a 

 knowledge on the spot of what we have found; 

 but the objects of our search are so minute, 

 that not much can be done in this way in the 

 field. 



How can I tell what to look for? the 

 youthful student may say. The answer to 

 which is, that in mass when growing, they 

 might be compared to brown jeUy, coating 

 other water-plants, or stones, or the surface 

 of mud at the bottom of the water. 



Spring and autumn are the most favour- 



portion with the hook, and transfer dexter- 

 ously to another bottle ; we shall find Melosi' 

 ras and Synedras. In small tributaries to the 

 main stream we may be fortunate enough to 

 obtain Campylodiscus costatus and C. spi- 

 ralis, princes of the tribe> and Surirellas, or 

 the exquisite Meridian. Boggy pools yield 

 some elegant species, as Eunotias, Himan- 

 tidia, not elsewhere to be had ; and wells of 

 spring-water, Tabellarias and some Dia- 

 tomas. In shallow streams stones may be 

 picked from the bottom containing interest- 

 ing species ; mountain torrents yield 

 Gomphonema geminatum, the finest of its 

 genus, and the curious Tetracyclus lacus- 

 iris. Encyonema may be met with where 



able periods for them. Suppose we are out 

 for the day on a Diatom-hunt, our pockets 

 stored with as many bottles as they wiU hold, 

 and the other necessary appliances with us : 

 we make for a stream and go up its banks ; 

 covering the stems and blades of grass over 

 which water flows, we may see this brown 

 jelly-like material, which is best got by 

 gently cutting off some of the blades of the 

 grass to which it is attached, and putting them 

 into a bottle, which is to be fiUed with water 

 to prevent shaking. CymbeUas and Gom- 

 phonemas are what we shall probably have 

 got. The white water- crowfoot, and grasses 

 growing towards the centre of the stream, 

 may be thickly covered at their floating 

 tips with brown waving threads ; cut off a 



water runs rapidly and constantly, as over 

 a dam. 



At the seaside we shall meet very dif- 

 ferent kinds ; as, growing on large or small 

 sea-weeds, the beautifvil flag-like Ac/man- 

 thes and Striatella, the Bhabdonemas and 

 Grammatophoras, fine Melosiras, and small 

 arborescent forms, from one to two inches 

 in length — these are Schizonemas. Also, 

 if very fortunate, Amphitetras, Biddulphia 

 pulchella and the Isthmias. Along the 

 sands of quiet bays, at about the line of 

 half-tide, in furrows constantly wet, many 

 interesting species may be found. To get 

 these in a state fit for carrying home, the 

 yellowish facing of the sand should be scraped 

 up with a spoon, and a quantity put into a 



