WYVILLE THOMSON 67 



new Pyrosoma of gigantic size, of which a magnificent speci- 

 men, measuring over f om* feet in length, was obtained in the 

 North Atlantic, but of which, unfortunately, only fragments 

 were preserved for study. Moseley, in his book, Notes hy a 

 Naturalist, tells us that the officers amused themselves by 

 writing their names with the finger on the surface of the 

 giant Pyrosoma, as it lay on deck in a tub at night, and the 

 names came out in a few seconds in letters of fire. 



Many interesting discoveries were made on the " Challen- 

 ger " in regard to the deep-sea fishes, which were shown to 

 extend down to no less than 2,750 fathoms. Perhaps the 

 most sensational novelty is the presence of light-producing 

 organs on the heads, gill-covers, and bodies of many abyssal 

 fishes, and apparently under the control of the animal's will. 

 Delicate organs of touch are in other cases associated with 

 imperfect eyes. All the deep-sea fishes are, however, modi- 

 fications of shallow- water forms, and none of them represent 

 types of earlier date than the Cretaceous period. 



No reference can be made here to the valuable reports 

 on Reptiles, Birds, and Mammals^nor to those on the 

 Botany and Anthropology of the various little-known lands 

 visited during the expedition. 



I am afraid that I have been able to give only a brief 

 and inadequate summary of some of the chief results of the 

 " Challenger " expedition, but I must not omit to point out 

 that one of the most important results is the improvement 

 in methods of investigation seen in later expeditions. It is 

 easy to criticize the " Challenger " equipment and methods, 

 and even the contents of some of the reports, but it must 

 be remembered that it all happened fifty years ago, and 

 that the methods of science may become old-fashioned in a 

 very few years. The naturalists on the " Challenger " were 

 the pioneers of deep-sea exploration, and their experiences 

 taught many lessons by which later expeditions profited. 

 Improved methods of capture of oceanic animals have resulted 



