1892. | Bacterial Investigation of the Sea. 317 
falls rapidly to 55° F. at a depth of 600 feet, and from this 
point downward there is no change. 
This season’s work which has been carried on at Wood's 
Holl in much more northern and cooler waters shows that the 
bacterial content of the sea bottom is very much less abund- 
ant at this point than in the Mediterranean. In the vicinity 
of Wood’s Holl Iwas unable to reach any great depth on 
account of the width of the shallow continental plateau which 
lies off southern New England and the middle Atlantic states. 
The’ number of bacteria per unit of volume was found to be, 
under similar conditions very much less than at Naples. The 
germ contents of the slime from Buzzard’s Bay averaged from 
10,000 to 30,000 germs per cc. This is scarce more than a 
tithe of what was present in the Mediterranean mud at equal 
depths. 
When we find the mud so much richer in bacteria than the 
two habitats are analogous or not. If we find the deposit 
made up entirely of species similar to those found in the water 
