but actually when bait fish which have died after several days in captivity 

 are subjected to a detailed examination, they do not all show such clearly 

 apparent injuries. From time to time these dead fish are discovered to 

 individuals which show only slight bleeding caused by the breaking of 

 subcutaneous tissue s The cause of these deaths ^ according to the teach- 

 ings of Professor Mita, is poisoning by the intermediate products of the 

 decomposition of protein, a subject which is under study at present in 

 forensic medicine. The protein that, when the animal is in a healthy 

 state, would already be changed into a nontoxic final product of metabolism 

 before being transported through the arteries invades the circulation 

 from the injured tissues while it is still in the toxic stage of an 

 intermediate metabolic product or visceral poison,, It is wondered whether 

 these deaths should not be interpreted as being due to poisoning from this 

 source o 



4) On the magnitude of the lethal external f orcein 



The author constructed the device shown in the following sketch and 

 carried out experiments to establish a general standard for the magnitude 

 of the external force that is lethal to bait fisho 



As the figure shows, the device consisted of a board made of 

 zelkovawood, with a vertical posto To the post a short tube was fastened 

 by one end in such a way that it could move up and down This tube 

 served to make the fish fall vertically, and experiments were made with 

 it fastened at heights of 20 em, 40 cm, and 80 cm. The fish dropped onto 

 the board by means of this tube were quickly marked and immediately released 

 in the live=pound Q (Such an experiment required only from 30 seconds to 

 1 minute,) The numbers of deaths that occurred during two days were com- 

 plied and compared. 



First Experiment Average Weight 22 , 5 gn>. Average Length 13,4 cm 

 Second w " " 20,7 " « w 12,3 " 

 Third " " M 23,0 « " M 13„5 " 



Of each of these groups of fish, 50 were dropped from each height 

 with the results shown in the following table /"Table 24_7„ From these 

 data it can be inferred that when bait fish like those used in these 

 tests are dropped vertically from heights of 40 can or more,, the external 

 force which they receive from the board on which they land is lethal. 



Death from Pathological Damage to the Blood Vessels 



When several days have passed after a school of fish is placed in a 

 live-pound, it begins to swim in an orderly fashion and in a definite 

 direction^') (mostly clockwise) around the circumference of a hypothetical 

 vertical axis at the center of the live=pound. Bait fish which have 



XII o Instructions were received from Technician Toru Sato and Attache 

 Susurou Kurita 



40 



