of the Fishery Board for Scotland. 177 



In the case of the sprats takfn in the Cromarty Firth on 1st June, 

 only a few were examined in regard to the reproductive organs, and I noted 

 that the females over 104mm. were spawning, and males of the same size 

 were also ripe, but it is possible that some under those sizes might also 

 have been found ripe if a fuller examination had been made of them. 

 The collection made on 31st March in the Dornoch Firth furnishes the 

 best material, because a larger number of them were examined, the sexes 

 determined, and the reproductive organs noted. Of the 870 obtained, 

 559 were males and 311 were females, and in some instances, males as 

 small as 84mm. had testes sufficiently developed to indicate that they 

 would probably spawn in the course of the season — at the close of which 

 they would have considerably increased in length. 



It was in this case, as in many others, difficult to divide the first series 

 — only the larger members of which were present — from the second series, 

 as is obvious from the curve (PI. IX, Fig. 5). The millimetre measure- 

 ments were as follows at and near the point selected : — 



100 101 102 103 104 105 106 107 I 108 109 110 111 112 113 

 10 10 10 9 11 15 21 9 8 14 10 13 30 39 



[Table 



