ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 1077 



them on the slide and spreads out and breaks up foreign gelatinous 

 masses with a curved glass neodle set in a match-stick as a handle. It 

 is useful to give a preliminary running over with 50-100 diamoters 

 for larger forms, and then, taking care that the pool is shallow 

 enough to avoid contact with the objective, and occasionally replac- 

 ing water lost by evaporation, run down with 1/4 in. or 1/8 in. 

 objective and take out the smaller species. Finding, for example, 

 a Pediastriim tetrus or small Cosmarium under the higher power, turn 

 on the 1 inch (a nose-piece is indispensable), run back, remove the 

 small speck and place him in the little pool containing his brethren 

 that have gone before him. Docidlum and long strings of filamentous 

 desmids are safely taken up by holding the tube in the direction of 

 their length and expelling them with the tube held nearly horizontal 

 to avoid injury from flexure. A very little experience will enable 

 tbe beginner to transfer with certainty, ease, and rapidity any 

 object he can make out under 250-500 diameters. 



This method is of course equally applicable to separating diatoms 

 or any minute objects which it may be desirable to preserve. Mosses, 

 &c, too large to enter the tubes can be sucked against their ends and 

 there held while being transferred. Further, in microchemistry, 

 minute crystals can be taken up from plant sections, moved to a clean 

 portion of the slide (or better, to a piece of thin cover-glass held in a 

 match-stick handle which admits the application of heat when needed) 

 and then treated with solvents, &c. For the use of reagents, in 

 order to avoid the undue multiplication of tubes and the contamina- 

 tion which would result from using the same tube for more than one 

 reagent, the author uses little test-points — formed by drawing out 

 small glass tubing — with bulging body and short tapering shank, 

 which is inserted in a small hole passing through a cork stopper, 

 which closes a glass tube (3 in. x 5/16), the other end of which is 

 drawn out and cut off to admit of substitution for a fishing tube. The 

 points are kept on a convenient tray or large watchglass, and being 

 charged with various liquids, permit the ready and perfectly control- 

 able application of any test or stain to very small quantities of 

 matter. Precipitates can be formed, redissolved, &c. 



The desmid tubes, test-points, &c, can be fashioned by any one 

 after a few minutes' practice from small glass tubing by aid of the 

 blow-pipe. A common kerosene lamp furnishes a good enough flame 

 for the purpose. To prevent blackening of the tubing (containing 

 lead) it must be kept out of the inner, luminous reducing flame. 



Collection and Treatment of Living Diatoms.* — Herr E. Debes 

 recommends the following articles as the necessary equipment when 

 in search of diatoms : — A bag or travelling satchel ; a number of wide- 

 necked glass bottles, with glass, cork, or caoutchouc stoppers. These 

 should be of two sizes, the larger, 1/3-1/2 litre, the smaller 1/6-1/4 

 litre ; a flat 4-6 in. net of thick gauze, fine book muslin, or any 

 other not too coarse tissue ; a tin spoon fitted with a screw, as well as 

 a telescope-stick, if possible, to which both can be screwed on. Also 



* Zeitschr. f. Wiss. Mikr., iii. (1886) pp. 27-38. 



