MUSEUM OF COMPARATIVE ZOOLOGY. 31 
warmer water, its velocities from little or nothing to five or six knots, 
and its endless counter currents and eddies, did produce such winrows 
on several occasions at great distances from the shore, — over 600 miles. 
That these accumulations of pelagic animals on the surface are intensified 
on calm, brilliant days, goes without saying. How far they retreat below 
the surface when they disappear, we do not yet know. Such accumula- 
tions continue sometimes for a whole season on the surface. We have 
had at Newport Salpæ rendering surface fishing absolutely useless for 
more than six weeks, and again Ctenophores have been as great pests for 
as long a period, later in the fall. 
The most extraordinary winrows I have met were off the Tortugas, 
about 150 miles to the northward, where the surface of the Gulf of 
Mexico for a whole day's steaming swarmed with Globigerin®. It was a 
dead calm. Again, steaming from the Tortugas to Key West, a distance 
of sixty miles, outside the reef, we kept in sight a long comparatively 
narrow line of Linerges all the way from one locality to the other, and it 
extended eastward as far as the eye could reach beyond the entrance 
to Key West harbor. 
Again, in the track of the Gulf Stream we passed for a quarter of a 
mile through a stretch of Trichodesmis of a width of about a hundred 
yards judging from the discoloration of the water. And in this last 
cruise, when about half-way from Cape San Francisco to the Galapagos, 
we remained for a whole day within the belt of a swarm of Nautilo- 
erapsus, the current running at the rate of nearly four knots in twenty- 
four hours. Again, for more than seven hours we steamed against a 
current of about three miles through a field of gigantic Salpa, which 
extended on each side of the ship as far as one could see. Finally, we 
passed through winrows of a new species of Siphonophore, a gigantic 
species allied to Praya, which filled the water in compact masses on all 
sides of us as we slowly forced our way through it between our dredging 
stations on the way to Cocos Island from Point Mala. 
Hensen, in his quantitative analysis of the pelagic fauna, does not seem 
to have given sufficient weight to the changes due to seasons, to currents 
and winds, and to local influences, and in his earliest experiments, dating 
back to 1882, and carried on from Kiel to the Danish islands, he has 
disregarded many important variables noticed by other observers, 
He himself mentions the sudden occurrence, on the Scottish coast,* of 
1 We should remember that all observations made on the Scottish coast, the 
North Sea, and Baltic are within the area of the 100 fathom line, and at no great 
distance from land. 
VOL. XXIII. — NO. 1. 3 
