ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



849 



(4) Swift's Penological Microscope (Fig. 155). — The general basis 

 of this is Mr. Swift's well-known " Challenge " stand (see Vol. I. (1881) 

 p. 810). A special arm carrying tho polarizer is added so that it can 



Fig. 155. 



