CuLGAN — Tropical Drift Seeds on Irish Atlantic Coasts. 47 



Botanical Characteristics ok the Iiasii Sea Drift. 



To complete this account of our Iiisli tropical seed drift, it may be well 

 to add a few details as to the nature and botanical Ijistory of its components. 

 Of the eight species set out iu the list given in the first section of this paper 

 no less than six — Entada scandens, Guilandina Bonduc, G. Bonducella, Mucuiia 

 wens, M. altissima, and Diodea reflexa — belong to the order Leguminosae, 

 one of the largest divisions of the vegetable kingdom. The seventh species, 

 Ilionwca tiibcrosa, is a member of an extensive genus of Convolvulaceae, and 

 the eighth, Saccoglottis amazonica, belongs to the order Humiriaceae which is 

 related to the Ericaceae or Heath family. All of these eight species produce 

 highly buoyant seeds or fruits. These have been tested by Dr. Guppy in the 

 course of his exhaustive experiments on the buoyancy of tropical drift fruits 

 or seeds, and several of them have been found to tioat for upwards of twelve 

 months. This buoyancy, he has shown, is not a constant character, but 

 depends on variable factors, such as station, stage of development, presence 

 of a vacant space between the cotyledons or, in the case of composite fruits, 

 abortion of ovules. All of these seeds and fruits he has found to be more or 

 less frequent or abundant in the beach drift of the West Indian Islands, 

 amongst which they are freely dispersed by sea currents in a germinable 

 condition, so that, with one exception, Saccoglottis, the species form a 

 characteristic feature in the strand flora. 



European knowledge of these exotic species began with a knowledge of 

 their seeds, which the enthusiastic botanists of the late sixteenth and early 

 seventeenth century eagerly collected, chiefly from Spanish and Portuguese 

 seamen engaged in trade with the Guinea coast or the Spanish Main. Fore- 

 most amongst these enthusiasts was the scholarly Charles de I'Ecluse (Clusius), 

 a native of L'Ecluse on the Sensee river in Artois, who in the course of an 

 enterprising botanical exploration of Spain and Portugal in 1546 had a leg 

 broken b}' a fall from his horse near Gibraltar, and was ever after condemned 

 to the use of crutches. His botanical ardour was not quenched, howevei", 

 for he continued his explorations and paid three visits to England, where he 

 obtained exotic seeds and fruits from his Loudon correspondents, James Garet, 

 perfumer, and Hugh Morgan and John Eizzio,^ apothecaries to Queen Elizabeth. 

 Here, too, he contrived to interview Drake on his return from his famous 

 circumnavigaticn of the globe, and to procure specimens of the much-prized 



' I have failed to ti-ace any relationship between this John Rizzio and the ill-fated 

 David Rizzio, French Secretary to Mary Queen of Scots. In the "Calendar of SUitc 

 Papers, Elizabeth, Domestic," p. 448, two Italians settled iu England, Justiniano and 

 Francis Ritzo, am mentioned as executors of the will of Sir Horatio Palavicini. 



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