14 Fishery Board for Scotland. 



full herrings got near the spawning-ground should be taken. A 

 herring is full when the ovary or testis is large enough to fill up the 

 abdomen and give the latter a firm, resistent feel. The term " full " 

 may be conveniently restricted to females in which the eggs are 1"0 mm. 

 and over in diameter and to males in which the testis is 2 cm. and 

 over in breadth. Small males were full although the testis did not 

 reach that breadth. For example, one full herring 17 cm. in length 

 had a testis 1 cm. in breadth. The herrings should be all. taken from 

 one shot, or from one fishing made at the spot. Full and spawning 

 herrings should be dealt with separately. 



The herrings should not be measured while they are in rigor mortis. 

 They should be preserved in formaline. Cold storage might be pre- 

 ferable, but that is not always available. The following method of 

 preservation suggests itself. The fishes should first of all be placed 

 loosely in troughs containing formaline solution (1 per cent, of formal- 

 dehyde in fresh water), care being taken to avoid distortion of the fishes 

 as far as possible. After being one day in the troughs the herrings are 

 to be removed and laid out, being straightened if necessary, on boards 

 with their left side upwards. They are left there for twenty-four 

 hours. They are then returned to the troughs, which have been 

 supplied with fresh formaline solution. A knife cut about 1 cm. 

 long should be made through the abdomen about the level of the 

 pectoral fins. The knife should pass right through the fish, through 

 the stomach or pyloric caeca. 



In order to test the effect on the measurements of the preservation 

 of the fish in formaline, a series of characters were measured on six 

 fresh herrings. The fishes were thereafter preserved in formaline 

 solution (1 per cent, formaldehyde in fresh water) for twenty- three days. 

 They were then remeasured, and the results are shown in the accom- 

 panying table. The letter " A " refers to the measurements made on 

 the fresh fishes, and " B " to these made on the preserved fishes. 



[Table. 



