284 KAMAKICHI KKHINOUYE : 



to make a large circuit if tbev intend to take food again near the same spot 

 as before. Generally they hesitate to swallow food, when it is too large for 

 a mouthful. As a rule they pui'sue food into shallower strata than those they 

 are accustomed to. While feeding, fishes in a school swim in different direc- 

 tions as they like. A fish which has taken plenty of natural food, is easier 

 enticed to baited hooks than one with an empty stomach. This may bs ex- 

 plained by the fact that the fish become fi'euzied from competition when feed- 

 ing in a school, and bite any object, suspended or moving in the watei', but 

 when they are not feeding they are rather shy and suspicious, and thus do not 

 easily bite baited hooks. When tunnies bite baited hooks, they swim down- 

 ward at once very quickly, about 200 m, more or less obliquely, so that tunny- 

 fishermen are provided with a sti'oug line, longer than 200 m. 



deyelop:ment and growth. 



The development of mackerels and certain seerfishes can be studied ; Imt 

 that of the plecostean fishes is very difficult to study, as these fishes do not 

 approach the land, at least in the spawning season. I have not yet succeeded 

 in obtaining these fishes with mature reproductive elements. Consequently the 

 larval and jx)stlarval i3shes of the Plecostei are still unknown. Two small 

 specimens described and figm-ed by Lütken (53) and identified to be the young 

 of T/nmmis dlalonga are the smallest examples, so far as I know ; but most 

 probably they do not belong to the Plecostei, as the foremost spine of the first 

 dorsal is remarkably shorter than succeeding spines. They would most probably 

 be immature forms of the Cybiidae, as the jaws aie long and the teeth large. An 

 immature sj^)ecimen caught in a tow-net during the Challenger Expedition, be- 

 tween the Admiralty Islands Jiud Japan, and described by Günthek (32) is 

 probably a plecostean flsh. 



In ÄLay, immature fishes of Scomler japonkm about 45 mm in length are 

 caught together ^^■ith colourless fries of the sardine, anchovy, etc. near the coast 

 on the Pacific side. These immature fishes 

 have slenderer body, rounded snout, teeth in ^^^^f:^^^ 

 the lower jaw iu two rows, but remarkably few % 



in number. In September they gi-ow to the ^'«- ^- ^"*"*"- ■'■"'*"""'*• ^■"'' ''^"■ 

 lengtli of about 12 cm, iu October 1 5 em, and when one j-ear old to 18 cm. I am 



