9 2 



PENNATULIDA. 



here, but only point out that the Pennatulids cannot be used to support it. But how is the fact to 

 be explained that the specimens of many species taken at great depths are exclusively or most 

 frequently young stages? 



The reason may possibly be that the severe conditions of life which are undoubtedly 

 found at great depths, check the growth, so that the few individuals which have emigrated from 

 better regions, become more or less dwarfed. But the reason may possibly be the more casual one 

 that hitherto the great depths have been fished so little and over so small an extent, and that the 

 apparatus used have been very defective. The Pennatulids found at the coast and in shallow water 

 and there regarded as common, often occur much scattered, sometimes in strictly local and limited 

 plantations*. Similar features are undoubtedly also found in the great depths; it has been pointed out 

 by Kolliker (Chall. Rep. p. 36) that the Challenger* obtained not a single Pennatulid in wide regions 

 of the oceans; of the 118 stations, at which the Ingolf used fishing gear on the bottom, only 17 

 have yielded Pennatulids; and large specimens of forms such as Penn. grandis, Funiculina, Halipteris, 

 Protoptilum etc. are seldom if ever got in the dredge, rarely enough in a trawl of the types generally 

 used in deep-sea researches; generally, we have to thank the lines of fishermen or their large, wide- 

 spreading nets for the large and entire specimens which give us correct ideas of these forms; and it 

 may upon the whole be said that we have only a full representation of these forms from regions, 

 where fishing has been far more intensely carried on than in the great depths. 



