mentioned for the determination of both the oxygen and the 
carbon dioxide. This involves the collection’ and shipment of 
eight bottles of water from each of the three stations—a total 
of about nine hundred and fifty samples being shipped in 1897 
and 1898. The water was collected with the plankton pump 
by means of a small pet cock imserted in the discharge pipe. 
A rubber tube is fastened upon this and inserted in the bottle 
and water sufficient to fill the bottle three times is pumped 
through it. The bottle is then closed, the sample being col- 
lected with a minimum contact with the air. If the change 
in the water between the time of collection and the time of 
analysis does not vwitiate the results, we shall find these gas 
determinations of great importance in the discussion of the 
plankton data. 
The equipment has been maintained in first-class condition 
so far as the wear and tear of property subject to the vicissi- 
tudes of an aquatic environment will permit. The hull of the 
laboratory boat has been provided with salt shelves and its 
bottom thoroughly salted to insure its preservation. The decks 
and guards have been painted repeatedly, and the canvas roof 
has received a heavy coat of paint. The floors have also been 
treated with several coats of oil. ‘Three years’ experience in 
our floating laboratory has only increased our satisfaction with 
its fitness and convenience for the work of a biological station. 
The steam launch, with the new equipment of machinery 
described in the last report, has been of great service. <A few 
repairs have been made from time to time upon the engine, and 
the boiler and stack have been provided with a shield to decrease 
heat in the launch. New tubes have also been placed in the 
boiler. In 1897 the steamer ‘Josie Sivley”’ collided with the 
‘“‘Tllini”’ while she was at anchor on the river front, and crush- 
ing her against the guard of the laboratory boat opened a seam 
upon the Jarboard side and broke several ribs and a stanchion. 
The launch sunk in shoal water and was easily raised, the 
damage being subsequently thoroughly repaired. In the spring 
of 1897 Mr. Newberry secured an engineer’s license, and has 
since cared for the launch. . 
During the session of the Summer School the carrying 
capacity of the launch is severely taxed in providing transit for 
