TRANSACTIONS OF MICROSCOPICAL SOCIETY. 
DESCRIPTION OF PLATE X, 
Illustrating Richard Beckys paper on so-called Podura Scales. 
A. — Upper side. 
B. — Group of scales. 
c. — Under side. 
rig. 
1. — Appearance of markings wlien the object-glass is corrected 
and the object is in focus. 
2. — The appearance a very little within or beyond the focus 
when the object-glass is well corrected. 
3. — Effect produced by fluid in scale. 
4. — The best focus when the object-glass is not well corrected. 
5 and 6. — The appearances within and beyond the focus when the 
object-glass is not well corrected. 
7, 8, and 9. — The markings as they appear in different positions, when 
illuminated from above, and as shown here, from the left- 
hand side. 
