134. DE. G. H. FOWLEE— BISCATAN PLANKTON : 



the dej)th *. In this as in similar tables in the earlier reports the excess of the caj)tures 

 at 50 fathoms over those at 25 and 75 fathoms is puzzling. 



On the other hand, although not essentially surface forms, they were distinctly 

 epiplanktonic, not descending to great depths. The specimens from 21 a, and from 

 36 f-l, may bave been captured at any point between their extreme depth and the 

 surface, but specimens from the closing-nets, marked E in the table (p. 135), were in all 

 cases few and fragmentary, and were probably dead specimens sinking to the bottom. 

 These Radiolaria probably did not live much below 100 fathoms. 



When the occurrences were plotted on " time-depth " tables, or " day, night, and rain " 

 tables, no evidence was forthcoming of any movement of these Radiolaria in response to 

 light, darkness, or rain. For example, Choenicosphcera llurrayaiia occurred at the 

 surface in 45 per cent, of the " day " hauls, 42 per cent, of the " night " hauls ; as it 

 also occurred at the surface in two out of the three " rain " hauls, we may conclude that 

 it does not sink in consequence of wet weather. We know from Prof. Brandt's experi- 

 ments that Thalassicolla can rise and sink with considerable rapidity in response 

 to stimuli, but unfortunately it was not captured sufficiently frequently to give any 

 indications. 



* The nine liauls with a net of 180 meslies per linear inch, referred to in previous reports, have again been 

 omitted. That they failed to catch even these Eadiolaria, which have no power of swimming, is a fairly conclusive 

 proof of the uselessness of such fine-mcshed nets for a general fauna, although doubtless necessary for Coccospheres, 

 Diatoms, and minute Protozoa. 



A^ 



