[139] 



1!)ow to prepare 3foraininifera. 



Second Paper. 



THE experience gained by washing shore-sand, and floating 

 off the Foraminifera, as described in a preceding Paper, 

 will prepare for the manipulations about to be described. 



Next to having the "material," a good supply of clean, fresh 

 water is essential. If water is "laid on,'' it will be found a great 

 convenience to have a piece of india-rubber tubing about a foot 

 long, to fit on the end of the water-cock, so as to be able to move 

 the jet of water to any part of the sieve, when washing the 

 material. By squeezing the end of this tube with the fingers, 

 the force of the jet may be increased, and a very fine stream 

 may be easily produced for washing the cleaned material to one 

 side of the sieve, just before tipping it on to the plate ; or a per- 

 forated cork may be fitted in, so as to insert a glass tube, drawn to 

 a fine point, which will give a jet with more convenience than a 

 washing-bottle. 



As to apparatus needed : — The sieve, before mentioned, (or 

 some modification of it,) being necessary, I will describe mine. 

 It is a strong zinc cylinder, open at each end, nine inches in 

 diameter and four inches deep, having a one-eighth-inch brass wire 

 round the mouth, and a similar, hvX finer wire round the bottom end. 

 Over this end is tightly tied with fine dry pack-thread, a djj piece 

 of millers' silk-gauze, i8o threads to the inch, which is pulled as 

 tight as possible, and well wetted with clean water every time 

 before using. By using this gauze we can easily and thoroughly 

 clean the sieve, by removing and well washing both gauze and 

 cylinder, and thus run no risk of mixing the species in "gatherings" 

 from different localities, — a point of essential importance in any 

 scientific investigation. The gauze should be cut with a good 

 margin, so that it may readily be replaced on the cylinder, and 

 being very durable, is no worse for being hemmed. By removing 

 the gauze, and tying a fine linen handkerchief loose over the 

 top, the cylinder will make a good bag or basin, which is sometimes 

 very desirable. I will call this sieve "number one."* Tin-plate 



* A very full description of the Sieve arrangement used on the " Porcupine," 

 etc., is given in " The Depths of the Sea," by C. Wyville Thomson, pp. 259 — 261, 

 The whole chapter will repay careful reading. 



