384 



P(U't III. — Tirpiitietli Anmud Report 



79-4 mm., and fifteen were males averaging 75-2 mm. On 12th 

 October the mixed series ranged from 66 to 97 mm., and averaged 

 81-6 mm., the females, eighty in number, having a mean size of 

 80-8 mm., and the 114 males a mean size of 82-2 mm. In December the 

 average of the mixed series was 82-0 mm., and the range from 68 to 

 103 mm.; twenty-three females averaged 85-4 mm., and twenty-one males 

 78-4 mm. In April the average for the mixed series of forty-three 

 fishes was 84-4 mm. and the range from 68 to 107 mm. ; the twenty- 

 nine females averaged 85-7 mm., and the foiu^teen males 80-6 mm. It 

 will be seen from this that the rate of growth of the series was very 

 slow, and although the number of specimens was not very large, I 

 think the averages fairly well represent the facts. From 1st August to 

 3rd April the average growth amounted only to 7-7 mm. The sexes of 

 the series in the early hauls were not completely determined ; but from 

 14th September to 3rd April tlie females increased from an average 

 size of 79-4 to 85-7 mm., and the males from 75-2 to 80-6 mm., an 

 increase in the former case of 6-3 mm., and in the latter of 5-4 mm. 

 In both cases it will be observed that the increment, whether for the 

 mixed series throughout the whole period, or for the males and females 

 from September to April, is less than with tlie first or younger series. 

 They appear to grow relatively more in autumn and winter than the 

 fishes a year older. 



If we now compare the mean size of this series with the mean size of 

 the previous series, the apparent increment of growth (in millimetres) 

 in the course of a year, as shown in the various hauls, is as 

 follows: — 



3Gth August. 14th Sept. 12th Oct. 

 34-1 32-6 32-7 



The mean annual increment from these observations is thus about 

 31-5 mm., or 1| inches. The diminishing increment shown is due to 

 'the relatively greater growth of the first or younger series in autumn 

 and winter above alluded to, which brings the averages closer together. 

 The growth. of this series may now be compared with the gi-owth of 

 the corresponding group on the East Coast, and I have given below th» 

 paiticulars for the northern part of the North Sea (ofi' the Shetlands) 

 (I.) and the deep water oft' Aberdeen (II.) : — 



15th to 18th Dee. 

 29-4 



3rd April. 

 28-9 



