ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



117 



(5) Mounting-, including- Slides, Preservative Fluids, etc. 



Preserving Fossil Seeds and Leaves.* — C. Reid and Eleanor M. 

 Reid treated the fossil seeds they had collected f in the following way. 

 A few seeds were removed from the store-bottles and washed in water to 

 remove the formalin or salicylic acid used for their temporary preserva- 

 tion. Then a thin film of wax (paraffin filtr., 45° C. G-riibler) was 

 melted on a glass plate or Microscope slide. The seeds or leaves were 

 placed, still wet, on the film, and the plate immediately heated to a 

 temperature just sufficient to melt the wax. By this procedure the seed 

 is impregnated with wax and rendered so tough that it could be easily 

 handled. The superfluous wax was then removed with blotting-paper, or 

 by brushing the surface with benzine. In the case of leaves it was 

 found best to place them between two glass plates charged with films of 

 wax ; they then become quite flat, and were easily photographed. When 

 the wax is hard one plate is warmed and slid off, and the exposed 

 surface of the leaf cleaned with benzine. The second glass was then 

 warmed until the leaf could be slid to a clean part of the 

 plate, and no excess of wax remained. The toughened 

 leaf could then be lifted off and mounted on a card like 

 an herbarium specimen. 



(6) Miscellaneous. 



Dust-excluding Histological Reagent Bottle.^ — 

 The bottle (fig. 25) devised by W. H. Harvey differs 

 from the ordinary type in the structure of the neck, 

 which ends abruptly without any lip. The pipette 

 has a glass cover or dome, through which it passes, 

 sufficiently large to receive the neck of the bottle. The 

 cover must be at least 1 mm. longer than the neck, 

 to prevent fracture at the union of pipette and cover. 

 As a further precaution, a thin rubber or felt washer 

 may be placed upon the shoulder of the bottle. 



Nathorst's Use of Collodion Imprints in the 

 Study of Fossil Plants. — By the term " collodion im- 

 print " is meant, says F. A. Bather,§ the impression of 

 any surface on a thin film of collodion. An impression 

 is obtained by letting a drop or two of collodion, dissolved in ether, fall 

 on the surface to be copied. The ether evaporates rapidly, so that the 

 film is hard in 2 or ?> minutes. When dry it is removed to a slide, and 

 preserved dry under a cover-slip held in position by gummed strips of 

 paper or by Canada balsam. When the imprint is very sharp, the film 

 may be preserved in glycerin-jelly without its distinctness being much 

 impaired. It is advisable to throw away the first made, as it usually 

 retains some dust from the surface of the object, the following films being 

 free from this. 



Fig. 25. 



* Vevh. k. Akad. Wetenscb. Amsterdam, xiii. (1907) pp. 1-26 (3 pis.). 



t See this Journal, ante, p. 108. 



t Zeitschr. wiss. Mikrosk., xxiv. (1907) p. 2S0 (1 fig.). 



§ Geol. Mag.,iv. (1907) pp. 437-40 (1 fig.). 



