32 CHARLES DARWIN 



no doubt many interesting facts, in relation to marine and 

 fresh water animals, might be observed in this chain of 

 lagoons, which skirt the coast of Brazil. M. Gay 2 has 

 stated that he found in the neighbourhood of Rio, shells of 

 the marine genera solen and mytilus, and fresh water am- 

 pullarise, living together in brackish water. I also frequently 

 observed in the lagoon near the Botanic Garden, where the 

 water is only a little less salt than in the sea, a species of 

 hydrophilus, very similar to a water-beetle common in the 

 ditches of England : in the same lake the only shell belonged 

 to a genus generally found in estuaries. 



Leaving the coast for a time, we again entered the forest. 

 The trees were very lofty, and remarkable, compared with 

 those of Europe, from the whiteness of their trunks. I see 

 by my note-book, " wonderful and beautiful, flowering para- 

 sites," invariably struck me as the most novel object in these 

 grand scenes. Travelling onwards we passed through tracts 

 of pasturage, much injured by the enormous conical ants' 

 nests, which were nearly twelve feet high. They gave to the 

 plain exactly the appearance of the mud volcanos at Jorullo, 

 as figured by Humboldt. We arrived at Engenhodo after it 

 was dark, having been ten hours on horseback. I never 

 ceased, during the whole journey, to be surprised at the 

 amount of labour which the horses were capable of endur- 

 ing; they appeared also to recover from any injury much 

 sooner than those of our English breed. The Vampire bat 

 is often the cause of much trouble, by biting the horses on 

 their withers. The injury is generally not so much owing 

 to the loss of blood, as to the inflammation which the pres- 

 sure of the saddle afterwards produces. The whole circum- 

 stance has lately been doubted in England; I was therefore 

 fortunate in being present when one (Desmodus d'orbignyi, 

 Wat.) was actually caught on a horse's back. We were 

 bivouacking late one evening near Coquimbo, in Chile, when 

 my servant, noticing that one of the horses was very restive, 

 went to see what was the matter, and fancying he could 

 distinguish something, suddenly put his hand on the beast's 

 withers, and secured the vampire. In the morning the spot 

 where the bite had been inflicted was easily distinguished 



a Annales des Sciences Naturelles for 1833. 



VOL. XXIX A HC 



