INVERTEBRATA, CRYPTOGAMIA, MICROSCOPY, ETC. 



523 



The mirror and suhstage are botli attached by sliding fittings to 

 the same bar, which carries them around the object as a centre. The 

 circular piece at right angles to the stage, gives steadiness to the bar, 



Fig. 39. 



with smooth movement, and is graduated to show the angular direction 

 of the illuininiiting pencil. 



Tlio liorscKlioo base is reversible, so that greater steadiness can 1x5 

 ensured wlicii the stand is used in a horizontal po.sition. 



Powell and Lealand's new ' "Water-immersion and -V Oil- 

 immersion. — At tho ConvorRaziono of tlic TJoyul Society, on April 28, 

 Messrs. Powell and Lcaland cxliibitcd their new formnln \ wator- 

 immorsion on Amphipleurn pelhiridn (dry) illuminated witli oblique 



2 M 2 



