234 Physalia Pelagica. 



The Brazilians call this creature tlie mourica, and the French 

 la fr eg ate. The body itself, npon which the sail-like ridge or 

 crest arises, is of a slight semi-diaphonous structure, and has 

 somewhat the aspect of an unusually solid soap bubble, glisten- 

 ing with a more than ordinary amount of iridescent hues. 



Although a native of the tropical seas, it is probable that 

 stormy weather, or a long continuation of south-westerly winds, 

 have occasionally carried specimens into the Mediterranean, in 

 the southern regions of which a Physalia might nourish for a 

 considerable time during the summer season, if general circum- 

 stances were favourable. It is only in this way that we can 

 account for the knowledge which Aristotle obtained of this sin- 

 gular creature. We know that through the munificence of his 

 patron, Alexander, he was enabled to employ collectors of 

 animals in the interior of Africa and in the far depths of Asia, 

 and in no other way could he have seen specimens of such 

 a vast number of animals of all classes, as he has accurately, or 

 at all events, unmistakeably described. W ell-preserved remains 

 of terrestrial animals, and of mauy kinds of fish, might reach 

 the great Greek naturalist in this manner ; but the evanescent 

 nature of the Physalia, which almost immediately loses its 

 beauty on being taken from its native element, would not, after 

 a long transit from distant regions, have reached him in such a 

 state as would enable him to describe it scientifically. So that, 

 unless specimens occur in the tropical parts of the Red Sea, 

 there is no other way of accounting for his possession of fresh 

 specimens. The supposition, however, of the Physalia being 

 occasionally carried into the Mediterranean will explain away 

 this difficulty ; and the case no doubt very frequently occurs, as 

 the specimen from which our illustration was drawn had been 

 driven by stress of weather as far north as the coast of the 

 Isle of Wight. In examining or describing a rare and curious 

 form of animal life, it is always interesting, as well as instruc- 

 tive, to retrace the course pursued by successive naturalists, in 

 their endeavours to assign to it a fitting name, and find out 

 its proper place in the scientific arrangement of the animal 

 kingdom. I shall therefore endeavour to follow the labours 

 of successive naturalists in their attempts to define the pre- 

 cise nature of the Physalia. The earliest modern name of 

 this zoophyte, Acalepha pelagica,* or sea nettle, is derived 

 from the ancient name conferred upon this class of marine 

 creatures by Aristotle, in consequence of the venomous sting 

 caused by the poisonous tentacula of several members of the 

 group ; a sting which leaves after it a white pimple precisely 

 similar in appearance to that caused by a nettle. Aristotle 

 included in this group the Actinias, now popularly known as 

 * A/caA.7j<£?7, a nettle, and IleAayos, the sea. 



