86 TRANSACTIONS LIVERPOOL BIOLOGICAT., SOCIETY. 
bay gave 5,050 and 2,480 respectively, and other examples 
of diverse results might be quoted from our records. But 
on the whole the impression received by an inspection of 
the forms for 1907 is that Ockopleura is more evenly 
distributed through the water than most of the other 
common organisms. 
In regard to the horizontal distribution, a mere 
inspection of our results shows in some cases close 
resemblances between adjacent stations (such as I and II) 
on the same day, or between adjacent days at the same 
station, and in other cases just as striking differences. 
How far these points of similarity and of divergence are 
normal and are fundamental, or how far they are due to 
wind, sun, and other weather conditions, or to tidal or 
other currents will require detailed consideration and com- 
parison with the results obtained in other years. 
A further point that has been brought out in the 
progress of this investigation is the obvious distribution 
of at least some organisms in swarms. This can 
occasionally be seen by the eye, when, for example, shoals 
of large Medusz are encountered which are so abundant 
for a limited area that on a calm day they may cover the 
surface like a tessellated pavement, and assume polygonal 
forms from mutual pressure. On other occasions the nets 
have evidently encountered swarms of Copepoda, of 
Cirripede Nauplii, of Crab Zoeas, of worm larve or of 
other organisms. One might expect such results in the 
case of neritic forms, which are merely stages in the life- 
history of some gregarious organism; but the occurrence 
is by no means confined to such, it extends to oceanic 
organisms on the high seas, and this sporadic distribution 
in swarms has not been sufficiently taken into account by 
some writers who have treated of the distribution of the 
plankton in recent years. 
