14 
INTRODUCTORY 
subject, to subjoin a comparative outline sketch of the 
two. 
Some of the errors with which naturalists have been 
involved, may have arisen from the great disproportion 
in size which exists between the male and female of 
these animals, and which is very great, the adult female 
bearing a proportion of only about one-fifth to the size 
of the large adult male ; but this is not altogether to be 
understood in regard of length, but of their general 
bulk, for the females are longer in proportion to their 
circumference than the males, being altogether more 
slenderly formed, which gives them that appearance of 
lightness and comparative weakness, which the females 
