circulation of the water in the deeper levels of the oceans. 

 Through an examination of the plankton, antarctic organisms 

 have been detected in the north Atlantic, and it has therefore 

 been suggested that a part of the north Atlantic water is of 

 antarctic origin ; but further than that little has been accom- 

 plished ; and unfortunately plankton organisms furnish the 

 least convincing data for a study of this kind. 



In the following pages I shall indicate, upon the basis of 

 the data afforded by the distribution of the recent crinoids (much 

 of it as yet unpublished) the general plan of the circulation of 

 the water in the deeper portions of the oceans, and shall show 

 that the littoral regions of the antarctic belong not with the 

 littoral regions of the remainder of the globe, but that the 

 water bathing them is an integral part of that system which 

 over the rest of the world constitutes the abysses. 



The Habits of the Crinoids. 



Before taking up the bearing of the distribution of the 

 recent crinoids upon the broader aspects of oceanography, it 

 is advisable briefly to explain the habits of these animals, and 

 to indicate the reason for considering their distribution as 

 significant in indicating the course of the deeper currents of 

 the oceans. 



The comatulids are at no time in their life history pelagic ; 

 the young are attached to the pinnules of the parent until 

 they are ready to affix themselves, when they are liberated 

 and, after a few hours, settle down as minute stalked crinoids. 

 After the loss of the stalk certain species may occasionally 

 swim about more or less, but so far as we know the great 

 majority of the species, and the great majority of the indi- 

 viduals of the few remaining species, attach themselves 

 practically for life. 



Thus the comatulids as a class are practically fixed bottom 

 living animals throughout life. We do not know the young 

 of any of the stalked crinoids, but there is no reason to suppose 

 that their young are pelagic, and the adults are even more 

 permanently fixed than are the adults of the comatulids. 



