108 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 
smaller tracts farther south, for transplanting to the eultivated beds. 
Oysters of the same species were likewise found at greater distances 
from the planted beds, in San Leandro Bay and at Sheep Island and 
Point San Pedro, attached to rocks and to piles driven in the bottom, 
leaving no room for doubt that they had originated through the spawn- 
ing of oysters in the bay. 
OFF MEXICO, CENTRAL AMERICA, AND THE GALAPAGOS ISLANDS. 
On January 30, 1890, the steamer Albatross left San Franciseo for 
Panama to engage in a special scientific inquiry, authorized by the 
President of the United States. The expedition was under the direc- 
tion of Prof. Alexander Agassiz, director of the Museum of Compara- 
tive Zoblogy at Harvard College, who also paid a large proportion of 
the expenses incidental to the cruise. The area marked out for inves- 
tigation lay off the western coast of Mexico and of Central and South 
America, from Cape San Francisco in the south to Guaymas in the 
north, and extended seaward to and including the Galapagos Islands. 
The biological and physical features of this region, as well as the con- 
tour and character of the bottom, except in the vicinity of the coast, 
were then almost entirely unknown, the Albatross having made only a 
few observations there during the voyage from Washington to San 
Francisco, while H. M. 8. Challenger, during her famous expedition 
around the world, sailed directly from the Sandwich Islands to Chile, 
and thence into the Atlantic Ocean. 
The present inquiry had reference mainly to the natural history and 
temperature of the deeper waters off the coast, at the bottom and sur- 
face, and also at intermediate depths. The ordinary outfit of the Alba- 
tross, frequently described in previous reports, was well adapted to the 
greater part of the observations, but for collecting organic forms at 
intermediate depths anew form of net was improvised by Capt. Tan- 
ner, and gave entire satisfaction. It is so arranged that after being 
lowered and dragged for any desired distance through the water it 
may be tightly closed by the falling of a messenger, thus preventing 
any objects from entering it while it is being hauled on board. It is, 
therefore, well suited for determining the character and amount of 
animal life at any depth below the surface, without the danger of its 
contents being added to at other levels. An appliance of this sort 
would have been of material assistance in the researches hitherto made 
respecting the mackerel-grounds on the Atlantic coast of the United 
States, and it is proposed to utilize the new invention during the future 
investigations in that region. 
Beginning off Cape Mala, near Panama, a line of stations was carried 
to Cocos Island, and thence, with some deviation toward the south, to 
Malpelo Island and back to Panama, where several short lines were 
run immediately outside of the 100-fathom curve. On the second cruise 
