168 Part III. — Ttventy-second Anmial Report 



as the mortality alluded to, that the conditions in this tank were not 

 satisfactory. The mean increase over the whole period was 35mm., or 1| 

 inches, the ten-day mean 2 •26mm., a little higher than that for the two 

 tanks referred to in the similar period. 



Among the cod the increase ranged in the first period from 24mm, to 

 48mm., the average mean being 33*9mm., and the ten-day mean 3'39mm., 

 and therefore a little less than Tank JSTo. 1. One of the codlings. No. 7, 

 was transferred to Tank No. 4 after this, and died four days later, like 

 the haddock and whiting above mentioned ; in this case the interval was 

 longer. In the second period the remaining fishes increased from 11mm. 

 to 48mm. in different cases, the average being 38"8mm., or about 

 1 1 inches. Omitting the smaller specimen, in which the increase was clearly 

 anomalous, the average increase of the others was 44-4mm., or 8'1 per ten 

 days. The increments in the length over the whole time varied from 

 35mm. to 95mm., the mean increase being 71 •7mm., or omitting the 

 anomalous form, 79mm., or 3g inches, the mean for ten days being 5'lmm. 



The single common dab in this tank increased by 15mm. in the first 

 period and by 10mm. in the second, the increment over the whole time 

 being 25mm., or 1 inch, and the average per 10 days I'filmm. 



In tank No. 4 there was at first some mortality owing to the vicis- 

 situdes in the temperature which, as already stated, affected different 

 fishes in different ways. 



Of three haddocks put in none survived the whole period, and only one 

 the first. One died after fifteen days ; it was 285m ra. and had increased 

 to 287mm. Another died after eighty-three clays, and it had increased 

 from 279 to 295mm. The third at the end of the first period increased 

 from 262 to 279mm., an increment of 17mm., the average per ten days 

 being the small one of l'7mm. It died from the high temperature a 

 few days later without having increased in length. 



Among the whitings there was less mortality, nine surviving the whole 

 time and other two for the first period. In the first hundred days the 

 variations in the increase were from 19mm. to 34mm., the mean being 

 27"5mm., or a little over an inch, the ten-day mean averaging 2"74mm. 

 In the second period the increments ranged from 9mm. to 19mm., the 

 mean being 15-7mm. and the average of the ten-day mean 2"85mm. 



Over the whole period the increments varied from 28mm. to 52mm., 

 the mean being 43' 1mm., about 1| inches, the mean increase in the 

 ten-day periods being 2"79mm. 



[Table. 



