532 SUMMARY OF CURRENT RESEARCHES RELATING TO 



water (and the contained algae) as it travels along, leaving the skin dry 

 behind it. It will then be seen that the knife does not really come in 

 contact with the alga; at all. 



The collected alga; may be enclosed in a collodion sack as before or 

 placed in a narrow vial and ran np into paraffin by carefully decanting 

 the successive liquids. When the paraffin is cooled the bottle is broken 

 and the block cut in the usual way. 



Rapid Method of Mounting in Aqueous Media.* — W. J. V. Ostcr- 

 hout has found the following method very successful. The examination 

 is made in a drop of fluid placed on a cover-glass 1 in. square, and 

 covered by a smaller one ; both rest on an ordinary slide. Excess of 

 fluid is removed so as to leave the margin of the larger cover-glass clean 

 and dry. A drop of balsam dissolved in xylene is placed on another 

 slide, and the cover-glasses placed thereon in an inverted position so as 

 to bring the smaller one underneath. The arrangement is shown in 

 section in fig. 121, s being the slide, m the material, cc the cover glasses, 



Fig. 121. 



and b the balsam. The balsam must be quite fluid, and pressure and 

 heat must be avoided. The preparation is then set aside to dry. Thick 

 specimens, such as free-hand sections, may be treated as follows : They 

 are placed on a slide in a drop of fluid, which is then surrounded by 

 broken fragments of cover-glass. A large cover-glass is then imposed 

 on these supports, the superfluous fluid is removed, and a drop of 

 balsam run in. The zone of contact afterwards becomes cloudy, but 

 this does not in any way detract from the value of the preparation. 



Simple Slide-holder.t — W. J. V. Osterhout states that a very satis- 

 factory holder for the simultaneous treatment of numerous slides can be 

 made out of nickel or copper-plated steel wire. This is wound round a 

 bar from \ to | the diameter desired for the coil, and should be ham- 

 mered while still closely wound on the bar. As both sides of the coil 

 are available, and as two slides placed back to back may be inserted in 

 each space, it is obvious that a very large number, over a hundred, may 

 be manipulated at the same time. 



Modification of the Rousselet Live-box.! — A. A. C. E. Merlin 

 draws attention to the following modification of Rousselet's live-box. 

 In order to retard evaporation the large cover-glass should be cemented 

 to the carrier, instead of being held loosely in it by the screw arrange- 

 ment, which is intended to facilitate the replacing of a fractured cover. 



* Univ. California Pub. Bot., ii. (1901) pp. 83-4 (1 fi?.). 



+ Tom. cit., pp. 81-2 (1 fig.). 



% Journ. Quekett Micr. Club., ix. (1905) pp. 169-70 (1 fig.). 



