MARINE BIOLOGICAL STATION AT PORT ERIN. 25 
Thursday— 10 a.m. Lecture on Quantitative Methods: in Plank- 
tology (Dr. Dakin). 
Afternoon. Dredging Expedition on S.Y. “ Ladybird.” 
Friday— 10 a.m. Lecture and Demonstration on Comparative 
Physiology of Marine Invertebrata (Dr. Roaf). 
Saturday— Morning. Lecture on the Sea as a Nutrient Fluid, etc. 
(Dr. Dakin). 
Followed by Plankton work in the Laboratory. 
Monday— Morning. Lecture on Oceanography and the Fisheries 
Mf 8 graphy 
(Professor Herdman). 
Followed by Plankton work in the Laboratory. 
Tuesday— Morning. Plankton work in the Laboratory. 
Afternoon. Dredging Expedition. 
Wednesday—Morning. Plankton work in the Laboratory. 
Examination of literature of the subject. 
The apparatus and methods employed in the actual 
enumeration of plankton organisms were demonstrated by 
Dr. Dakin. The microscope used, which has proved 
exceedingly efficient, is one of the new Leitz’ stands 
which allows room on the stage for a somewhat large 
plate. The largest mechanical stage made by the same 
makers gives more than enough play. Glass counting 
plates have been obtained from Zwickerts of Kiel, and 
these with Hensen’s “* Stempel-pipetten ’? completed the 
apparatus used for this part of the work. In connection 
with this side of the biological work, the defects and 
inaccuracies of quantitative plankton studies were treated 
in detail, and the object of the rather monotonous series 
of counts was explained. Dr. Dakin hopes next summer 
to be able to compare some of the results obtained during 
a quantitative examination of the freshwater plankton of 
Lough Neagh, in Ireland, with those obtained in the 
Irish Sea during past years. 
Another subject which was treated in our course at 
Port Erin, and which opens up an interesting field for 
future research, is the question of the food of marine 
animals. The credit of drawing the attention of 
Zoologists to this important subject—important from the 
