I 



SEA-FISHERIES LABORATORY. 235 



Here, out in the middle of the channel between 

 Ireland and the Isle of Man, the depth was about 65 

 fathoms, and we sank our vertical nets down to 60, and 

 hauled them up through the lower ten fathoms (I), the 

 lower thirty (II), and the entire depth (III), then through 

 the zones 30 to 20 (IT), twenty to ten (V), and ten to five 

 (YI). That brought us in touch with the surface zone 

 through which the weight-net, the shear-nets and the 

 surface-nets had ranged. In this way we hoped to be able 

 to localise the constituents of the fauna obtained in a 

 vertical haul such as III. 



It is clear that much further work in this direction 

 is needed. Some of these serial hauls support the idea 

 that there is a definite zone beneath the surface holding 

 the maximum of organisms ; but other hauls again seem 

 to give contradictory evidence. For example, in the 

 Hensen net hauls represented in the diagram (fig. 5) 

 dealing with September 12th, Hensen I and Hensen II 

 and Hensen IY all contained very small quantities of 

 material, 0*1 c.c, each, while Hensen YI contained a very 

 little more, 0"15 c.c. Hensen III, open all the way from 

 the bottom to the surface, contained distinctly more 

 material, 0'25 c.c, and Hensen YI drawn through a 

 narrow zone of five fathoms only (ten to five fathoms) 

 contained as much as Hensen III, indicating that most of 

 the organisms were on this occasion contained in this 

 narrow zone between ^.Ye and ten fathoms. The Nansen 

 hauls, on the other hand, did not bear this out, No. II 

 and No. Y containing more than either III or YI. 



We feel that we have not yet sufficient data as to 

 these serial vertical hauls to make it possible to discuss 

 the matter of zonal distribution further at present, 



