CURRENT-CONNECTIONS IN S. HEMISPHERE 305 



A bottle (No. 37) , which was dropped over in about lat. 16° S. and 

 long. 98° E., nearly 1000 miles north-west of the North-west Cape 

 of Australia, was recovered on the south-east side of Madagascar. 

 Presumably it represents the course taken by drift from the vicinity 

 of this corner of Australia. After a drift westward of about 1100 

 miles, it crossed in about lat. 15° S. and near the 80th meridian 

 of east longitude the starting-place of two bottles (18 and 38 of 

 Schott's Chart 5, and mentioned on p. 22) only 120 miles east and 

 west of each other, one of which was stranded on the African coast 

 immediately north of Zanzibar, whilst the other was thrown up on 

 the south-east shores of Madagascar. Schott lays down the tracks 

 of bottles from the southern end of Madagascar and its vicinity, 

 which, after getting into the Natal Current, were beached on the 

 south coast of Cape Colony east of Cape Agulhas. We thus perceive 

 how seed-drift from Western Australia may be distributed on the 

 East Coast of Africa from Zanzibar to the southern extreme of the 

 continent. 



But as regards Australia, Africa may be a giver as well as a re- 

 ceiver. Drift from the southern extreme may be carried by the 

 Agulhas Current into the West Wind Drift Current and thus to the 

 south coasts of Australia. Of this a suggestive example is afforded 

 by a bottle, thrown overboard about seventy miles south-east of 

 Cape Agulhas, which was stranded on the shores of the Great Aus- 

 tralian Bight (Schott, Map 5, No. 31). However, the Agulhas 

 Current has a subsidiary branch that doubles the Cape, and as 

 indicated by the bottle-drift data (see p. 63), may bear drift from 

 the shores of Natal and from the south-east coasts of Cape Colony 

 to the African West Coasts. Though the event is probably infrequent, 

 seeds could be transferred in this way from the east to the west 

 side of the continent. It is even possible that drift from Western 

 Australia, after traversing the Indian Ocean to the south of Mada- 

 gascar might in this manner reach the South-west Coast of Africa. 



It is likely that drift in its passage from South Africa towards 

 Australia may at times perform the circuit of the Indian Ocean. 

 South African drift, after crossing the ocean in the West Wind 

 Current, may be carried north in the West Australian branch of 

 the current into the South-east Trade belt, and thence across the 

 ocean to Africa, thus completing the circuit of the Indian Ocean. 

 Wood-Jones (p. 295) refers to a bottle " launched in Mauritius " that 

 is said to have reached Keeling Atoll. No other data are given; 

 but he is quite justified in assuming that it " almost certainly came 

 to the atoll from the eastward, after completing an enormous circuit 

 of the Indian Ocean." This bottle would have followed the track,, 

 above indicated, to the south of Madagascar and towards the southern 

 extreme of Africa, subsequently crossing the Indian Ocean in the 

 belt of the Roaring Forties, and turning north in the West Australian 

 Current to meet the South Equatorial Current (South-east Trade 

 Drift) that flows past Keeling Atoll. It would have accomplished 

 about 10,000 miles in about three years. 



The Influence of the Current- Connections in the Southern 

 Hemisphere on the Distribution of Littoral and Estuarine 

 x 



