THE SHARK THAT HIBERNATES — MATTHEWS 421 



which is presumably a random sample, the females outnumber the 

 males by 30 or 40 to 1. It is unlikely that these figures are the true sex 

 ratio of the population. Where are the other males ? Do they habitu- 

 ally swim at greater depths, and come to the surface only in quest 

 of the females? Are they shyer of the predacious fisherman? Or 

 is there a social structure in the population so that dominant males 

 herd harem schools of females and keep their rivals at a distance? 

 Some fortunate naturalist may one day be able to find the answers to 

 this and many other riddles about these interesting creatures. 



