42 



INTERESTING FACTS. 



their bodies,) but by moving them about it could 

 be reproduced for some Jength of time after. 

 As long as the luminosity of the ocean was 

 visible, (which continued most part of the 

 night,) a number of Pyrosoma atlanticum, two 

 species of Phyllosoma, an animal apparently 

 allied to Leptocephalus, as well as several crus- 

 taceous animals, all of which I had before con- 

 sidered as inter-tropical species, were caught and 

 preserved. At half-past ten, p. m. the tempera- 

 ture of the atmosphere on deck was 52°, and that 

 of the water 51i°. The luminosity of the water 

 gradually decreased during the night, and to- 

 wards morning was no longer seen, nor on any 

 subsequent night.* 



Albicores,t bonitos, and even a colossal whale 



* How will this accord with the geographical distribution 

 of the mollusca by Peron and Leseur ? After studying the 

 Holothuria Medusa, and other congeners of delicate and 

 changeable forms, they came to the conclusion that each 

 kind has its place of residence determined by the tempe- 

 rature necessary to support its existence. Thus, for ex- 

 ample, they found the abode of Pyrosoma atlanticum to be 

 confined to one particular region of the Atlantic Ocean. 

 — Voy. aux Terres Aust. torn. 1, p. 492, quoted in Lyells 

 Principles of Geology, vol. ii. pp. Ill, 112. 



\ Albicores, bonitos, and dolphins, often follow the ship 

 for several days in succession; we had occasion to note 

 an albicore that was marked on the back by some sharp in- 

 strument, leaving a large sear by which it could readily be 



