The Diffusion of Species

Abstract

THE vast and altogether exceptional assemblage of Salpæ mentioned in NATURE (September 11, p. 462) by the Duke of Argyll as having been observed by him whilst recently cruising in the Hebridean seas, was due, in all probability, to the extension in a north-easterly direction of the ordinary surface-current of the Atlantic, or to an unusually long continuance of steady south-westerly wind, the effect of which would be to drive the superficial water of the Atlantic before it to the British coasts, and, with the water, the enormous multitudes of Salpæ which are occasionally to be met with in the latitude of the Canaries and Cape Verd Islands.¹