PKOGRESS IN BIOLOGICAL INQUIRIES 13 



In Maine, fresh-water streams flowing directly into tidal water 

 come under the jurisdiction of the Inland Fish and Game Commis- 

 sion instead of the Sea and Shore Fishery Commission, and the law 

 permitting fishing for fresh-water or lake smelts during their breeding 

 season applies on these streams. As smelts can breed only in fresh- 

 water streams, the marine smelt is afforded no protection during the 

 spawning runs. A law should be made distinguishing between tide 

 water and lake tributaries, and the protective law of the Sea and 

 Shore Fishery Commission should be extended to cover the former. 



The analysis of the data pertaining to the fresh-water smelts is still 

 in progress. The smelts of the lakes afford entirely different problems 

 from those of the salt-water fish, and it is anticipated that these will 

 be worked out, as far as the data will permit, in the near future. 



LARVAL FISHES 



An unusual opportunity was afforded by the Arcturus expedition 

 (see account under heading "Oceanography") for the study of larval 

 fishes, their distribution over large areas in the Atlantic and Pacific 

 Oceans, their embryology, food, and enemies, the description of 

 unknown forms as well as of new stages of known species, and a study 

 of the conditions of life under which they exist in the open sea. The 

 examination of the young fishes collected by the expedition is being 

 carried on by Marie Poland Fish. 



Throughout the cruise, larval and postlarval fishes were found dis- 

 tributed everywhere over the ocean, but the number of species and 

 the actual abundance of specimens were strikingly different in the 

 various regions investigated. From Bermuda southward, in the Sar- 

 gasso Sea area, every haul of the plankton nets and Petersen trawls 

 yielded quantities of young fishes, often 10 to 20 species at a time. 

 Although this part of the Atlantic had been visited by heavy storms 

 for some weeks, the larval fishes seemed to thrive well, if one can 

 judge from the immense number of uninjured specimens taken. It 

 would appear, also, from the collections made here, in a region where 

 conditions typical of the open sea exist, that by far the greatest pro- 

 portion of ocean fishes spend the early part of their lives at the sur- 

 face. Of 40 species recorded and described by Mrs. Fish in late 

 February and early March, approximately SO per cent were found 

 always at the surface, 10 per cent at depths of 100 to 200 meters, 

 and 10 per cent below these depths. 



The Pacific Ocean, in contrast to the Atlantic, although swarming 

 with animal life, yielded relatively few larval and postlarval fishes 

 from March until the middle of June. Although nearly every haul 

 brought in a few larvse, and the number of species represented over 

 the whole period was no less, the total number of specimens was much 

 smaller than in the Atlantic during late February, March, and July. 



The embryology and early development has been worked out for 

 five species of flying fish obtained during the cruise, some of them 

 from nests of Sargassum weed bound together by tough threads of 

 secreted material. The unusual modification of the fins was found 

 to be evident even in the egg. The eggs of 15 different fishes, 

 the development of which was previously unknown, were hatched 

 in the laboratory. At the completion of the expedition, 161 species 



