ZOOLOGY AND BOTANY, .MICROSCOPY, ETC. Ill 



Simple Shaker.* — K. Poppe describes a new type of shaker, worked 

 by a water turbine (fig. lfi). The rockers a b, ab, which work round 

 the axes a, a', support a carriage, the base of which is hinged to a con- 

 necting rod attached excentrically to the revolving wheel. On the 

 platform c can be placed a tray (not illustrated) for carrying test-tubes 

 horizontally. The upper stage, for carrying flasks, is attached by means 



Fig. 16. 



of wing screws. The flasks are kept in position by means of a movable 

 plate d. The whole apparatus is small enough to go into a medium-sized 

 incubator. 



Fixation and Embedding of Embryological Material, f — 

 H. Schridde, from a long experience, finds that Orth's mixture of 

 Miiller's fluid and formalin (I) : 1) is the best fixative for the purpose. 

 The fluid should be warm. Small objects should remain at a tempera- 

 ture of 36° in the mixture for 1 to (5 hours. Large specimens require 

 from 12 to 24 hours. On removal the preparations are placed in 

 running water for from 3 to 12 hours, and then transferred to 50 p.c. 

 alcohol. When required for embedding they are passed through up- 

 graded alcohols to absolute alcohol, after which they are transferred to 

 cedar-wood oil, wherein they remain until they are quite clear. After 

 this the preparations are immersed in xylol or toluol for 20 to 30 

 minutes, according to size. This procedure is followed by paraffin 

 m.p. 42°-44°: small objects 15 to 30 minutes, the larger one, 30 to 60 

 minutes. After this they are transferred to paraffin m.p. 51°-56°,- in 

 which they remain for f to 1 hour. For large objects an intermediate 



* Centralbl. Bakt., lte Abt., Orig., lv. (1910) pp. 527-8. 

 t Zeitschr. wiss. Mikrosk., xxvii. (1910) pp. 360-5. 



