127] THE GOLDFISH AS A TEST ANIMAL— POWERS 



INTRODUCTION 



The need of uniformity of remedial agents has long been recognized among 

 therapeutists and pharmacologists. When the physiological activity of an 

 agent is associated wdth or dependent upon its chemical constitution which 

 can be determined by analysis the problem becomes a simple one. On the 

 other hand when either the chemical constitution can not be determined or 

 the activity of the substance is dependent upon some other factor independent 

 of its constitution the problem becomes more complex. This difficulty has 

 been overcome with more or less success by certain physiological assay methods, 

 the history of which it is not deemed necessary to present as Baker (1913) 

 has given an excellent review of the Uterature up to that date. Of the methods 

 employed at present the most favored is Fagge and Stevenson's (1866) frog 

 method as proposed by Houghton (1898) or some modification of it. Others 

 have been suggested: — the blood pressure method, the guinea-pig method 

 introduced by Laborde (1884) and further worked out by Reed and Vander- 

 kleed (1908), the cat method of Hatcher and Brody (1910), the cockscomb 

 method of Haskell (1914), the goldfish method of Pittenger and Vanderkleed 

 (1915) , and other methods. 



The purpose of this investigation was to test the vaHdity of the Pittenger 

 and Vanderkleed goldfish method or to work out a usable modification of it. 

 The problem then involved the development of a method and technic by which 

 drugs or remedial agents, not readily assayed chemically, could be assayed 

 or standardized physiologically by means of goldfish. In order to use the 

 goldfish as test animals they must meet the following requirements: 1. They 

 must be relatively constant in their reactions or resistance to the drug or 

 agent to be standardized or at least there must be a constant seasonal rhythm. 

 2. They should be capable of being standardized with some standard of a 

 conveniently assayable substance if seasonal rhythm is present. 3. They 

 must be relatively sensitive to small variations in the concentration of the 

 substance to be tested. 



MATERIALS AND METHODS OF STUDY 



A series of experiments was run with the goldfish to determine how far 

 they would comply with the three requirements just mentioned. In order 

 to do this the goldfish were tested with a number of substances varying in 

 toxic activities. A number of solutions of each substance tested were pre- 

 pared of which the concentration of each differed only 10% or less from that 

 of the one next to it in the series. Two goldfish of known weights were then 

 placed in two Hters of each of the solutions contained in a three Hter wide- 

 mouth bottle. The survival time of each fish in each solution was noted 

 and recorded. The bottles were kept stoppered when volatile substances 



