A STUDY IN PLANKTON. 
This year the comparative results in a series of Plankton 
determinations in a quantitative sense were so striking that I 
photographed the bottles containing the material together as the best 
means of demonstrating them. These were made as will be seen 
between the 19th and 23rd June, first at Cullcrcoats on the 
southern part of the Northumberland coast, and in the case of the 
others in the neighbourhood of the Fames and Holy Island in the 
northern part of the district. The dark contents represent the 
catch for about an equal time on each occasion, and the variable 
quantity of surface and mid-water life obtained is quite apparent. 
The general character of the contents may be brielly stated : — 
1. Cullcrcoats, surface, 19 June. 
Egg of gurnard — one. 
Medusoids : Thaumantias, several. 
Snrsia tubulosa, Sars, several. 
Copepoda : Calanus finmarchicus, several. 
Acartia longiremis , very numerous. 
Cladocera: Evadne nordmanni and other Cladocera, numerous. 
2. Skate Roads, surface, 21 June. 
Pelagic ova, numerous. 
Weever, Trachinus ripera, say 70. 
Gurnard, Trigla gurnard us, say 10. 
Five-bearded Rockling, Onos mustela, say 30. 
Copepoda : Calanus finmarchicus, numerous. 
Anomalocera patersoni. several. 
Temora longicornis, very common. 
Pseudocalauus elongatus, common. 
Centropages typicus, several. 
Oithona spinifrons, several. 
Cladocera : Eradne nordmanni , common. 
Plt'opis polgphemoides , very common. 
8. Inner Fame, mid-water — near bottom, 22 June. 
Pelagic Ova, none. 
Beroe and medusoids (principally Thaumantias), numerous. 
Copepoda : Calanus finmarchicus, numerous. 
Temora longicornis, ,, 
Acartia longiremis , ,. 
Pseudocalanus elongatus , several. 
