AMPLIFICATIONS 63 



be filled with admiration at the marvellous 

 creative power lavished upon the organisation 

 of these lowly creatures. 



The illustration of the whelk's radula (Fig. 11) 

 is from a negative of 100 diameters ; the objec- 

 tive used was the half-inch and the focal length 

 50 inches. 



That represented in Fig. 12 is from a negative 

 of 80 diameters ; the objective was the half -inch 

 and the focal distance was 40 inches. 



The radula of the limpet (Fig. 13) is illus- 

 trated from a photo-micrograph representing 

 the object amplified to 100 diameters; the 

 objective used was the half -inch and the focal 

 distance was 50 inches. 



The Cirri of Barnacle. 



The word * cirri ' is from cirrus, * a lock of 

 hair.' 



Both the chief representatives of the Order 

 Cirripedia, viz., the Lepas or Barnacles, and 

 the Balani or Acorn-shells, possess several 

 pairs, generally six, of the appendages as 

 shown in the illustration. 



