CONSTANT DIFFERENTIAL GROWTH-RATIOS 23 



Dimensions (in inches) of Parts of the Bill and Casque of the 

 Hornbill Antheracoceros malaganus (from E. Banks, unpublished) 



* Indistinguishable from bill. 



Both in length and height the casque is highly heterogonic 

 relative to the length and /or the height of the bill proper. 



■ 50 



/ 



100 



- 20 



20 

 1 



50 



100 



200 mm, 



1 ' ' 



Fig. 13. — Increase of interocular distance with carapace width in the crabs 

 Cancer (i) and Eriphia (3), and of carapace length with carapace width in 



Cancer (2) ; logarithmic plotting. 

 k for interocular distance, in Cancer 0-70, in Eriphia 0-76. 



