180 University of California Publications in Zoology ‘Vou. 9 
gy 
15. One hundred water-sample bottles for gas analysis, with 
cases. 
16. Three hundred water-sample bottles with patent closure, 
with cases. 
17. One electric hghted photometer for measuring the in- 
tensity of daylight. 
18. A large supply of glass jars and carboys as containers of 
biological specimens and water samples. 
Items 2, 6, 7, 12, 13, 14, 15, and 16 are the apparatus used in 
the international researches on the oceanic areas of northern 
Europe, and were purchased through the Central Laboratory of 
the International Commission at Christiana. Items 5, 9, 10, 11, 
and 17 were designed and constructed in San Diego and Berkeley. 
Items 1, 3, 4, and 18 are commercial articles and purchasable 
from dealers in such things. Item 8 was made for Mr. Alexander 
Agassiz, and given by him to the station. 
4. MeruHop of PROCEDURE 
Experience gained during the earlier years of general explora- 
tion of the San Diego region demonstrated that correlations be- 
tween organisms and their environment are by far too complex to 
be revealed from data obtained by the usual methods of collecting. 
Variations in light and in currents, temperature, density, and 
gas-content of the water, as well as in many other factors, largely 
determine the vertical and horizontal movements of organisms 
and likewise their abundance at any particular depth at any 
particular time and place. Consequently a very careful plan of 
collecting would be required if the data obtained were to yield 
the information sought. 
In preparing such a plan two fundamentally important con- 
siderations are involved. First, the plan must be workable from 
the standpoint of available equipment, for a plan admirably 
adapted to a large boat like the ‘‘ Albatross’’ for example, would 
scarcely suit the ‘‘Agassiz.’’ Not only must the size of the boat 
and the number of the crew be considered, but its speed, draft, 
and in fact its entire design must be taken into account. Again 
the need of accurate positions while collecting requires that 
