ERRATA. 



Pg. 13, last line, for "translucent" read "transparent." Pg. 32, 5th from bottom, 

 for "cilary " read "ciliary." Pg. 97, 2nd line, for "which" read "and; " 10th line, the 

 body "of the cell." Pg. 98, last line but one, for "acina" read "acini." Pg. 100, line 10, 

 for "spith" read "cells." Pg. 163, line 4, after "place it in B" add "nearly fill C with 

 water." 



