ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



645 



spring-tooth. There is an iris-diaphragm, and a removable illumination 

 system. The analyser can be put in and taken out without interference 

 with the adjustment of the instrument. There is a second analyser over 

 the ocular, with a circumference divided into 360 degrees. The instru- 

 ment has a quartz plate and an opening for inserting a quartz wedge. It 

 is also equipped with Bertrand lens, Grlans prisms, and an object-centring 



arrangement. 



Fig. 146. 



Reichert's Large Stand, A 1.*— This stand, which was figured and 

 described in this Journal for 1905 (p. 241) is now made with a gradua- 

 tion on the limb, to assist in the focusing of high-power objectives and 

 to prevent injury to slides. | 



Reichert's New Preparation Microscope.^ — This Microscope, listed 

 as No. 131, has a prism tube (fig. 146), with erecting Porro-prisms 



* C. Beichert, Vienna, Catalogue, Mikroscope, No. 26 (1908) p. 16, fig. 6. 

 t It is interesting to note that limb-graduation was first introduced by 

 John Marshall in 1704. — Ed. 



X C. Reichert, Vienna, Catalogue, Mikroscope, No. 26 (1908) p. 47, fig. 40. 



