SOURCES OF MARINE FOOD. 
363 
Although I do not think it is safe to depend upon all the relative details of this 
table on account of the two deficient samples, yet certain conclusions are evidently 
admissible. In the first place even the two available samples of the vertical taken 
at Station A show beyond a doubt that the Chcvtoceros had not then attained at that 
locality the great abundance which they showed at the later dates heretofore described, 
while at all the succeeding stations they extend much farther from the shore in 
considerable quantities, as at B and C, and at D in much greater proportion than 
they did two weeks later. 
It is also to be noted that Lauderia was at this earlier date much more abundant 
than on the two subsequent dates described here, being by far the most characteristic 
organism at Station D ; of 78 bottom organisms at this locality, 70 were Lauderia 
of one, or at most two, species. There was at this time also relatively very little of 
the flocculent amorphous debris suspended in the water at Station D. 
The above table also shows the increase of micro-organisms at Stations B and 0, 
and agrees with the two preceding ones in showing more organisms at the surface 
than occur at either mid-depth, or at bottom where there are least. 
The extent to which the Plankton of Buzzards Bay may be shifted by the tidal 
currents might be tested by running this same longitudinal section on an ebbing tide 
by which the ship would register a somewhat different set of conditions from those 
here recorded, while the line should be extended out as far at least as the Gulf 
Stream (60 miles distant) in order to show the relation between the offshore and 
littoral quantities and distribution of these and other forms as they might occur. 
The section across the bay (plate 64, Stations I-V) was designed to get as near a 
synchronous series of observations as was possible upon any given tide or fraction 
thereof. The whole distance was divided into four equal intervals, the stations being 
then about a mile and a half apart, and a vertical of surface, mid-depth, and bottom 
samples was taken at each station. 
Letter 1ST, shown by the platting on plate 70, represents the distribution of this 
material under consideration in a cross section of Buzzards Bay on the day following 
the longitudinal section given on plate 68, and there is a great regularity in the results 
obtained. The irregularity is confined almost entirely to the one group Cluetoceros 
(plus the Melosira costata) which from Station IY begin to increase very rapidly for 
the last mile of the course to Station V at surface, mid-depth, and bottom samples in 
the same manner, until at the last collecting point, Station V, they form by far the 
greater part of the aggregate organisms and, as in previous instances of the kind 
already cited, the other organisms are especially few. 
Of such other organisms except Cluetoceros , the general rule is that they gradually 
increase as one approaches the middle of the section, and then decrease again as the 
other limit is reached; this is especially noticeable in the group Melosira , which is the 
chief element as regards abundance and continuity in occurrence in these cross-section 
analyses. The copepods also conform to the same distribution, i. e., are more abun- 
dant at the middle portion of the bay than at either end. 
