86 Sprats Spawning, Growth, Food. 



record of eggs and larvae collected thereabouts, verifies the 

 idea of their transportation from the outer to the inner 

 waters of the Sound. Our inquiry into the subject at the 

 Thames mouth is in favour of Cunningham's view. 



Prior to and when the full-roed sprats are leaving the 

 estuary in the spring there is no appearance of eggs or spent 

 fish (one noted above) remaining in the river, nor evidence 

 of breeders about afterwards, until their return the following 

 winter. Furthermore, it is subsequent to the adults' departure 

 that the larval forms begin to swarm from the West Swin and 

 Barrow Deep, and advance up stream. Ostensibly a similar set 

 of phenomena occurs in the North. Witness Masterman's 

 analysis of the work of the " Garland " in the Firth of Forth 

 under the auspices of the Scotch Fishery Board (I. c.). His data 

 and admission of the eggs drift from E. to W., and their 

 further spread, according to directions of wind and tide, does 

 not, however, substantiate the sprats' spawning ground to be 

 in the brackish water of the inner Firth or estuary, as he and 

 Mclntosh believe. 



The rate of growth of the sprat we shall have something to 

 say about under Whitebait (posted). 



As to their food, this in a great many instances is often past 

 recognition, partly from its original delicate nature, and from 

 its quick digestion. Frequently gelatinous glairy substance 

 (as in the herring's stomach) alone remains. In December we 

 have found Mysidas and Copepods. In January Amphipods, 

 Copepods, and remnants of crustacean larvse ; in one large 

 female was an annelid, but this worm was not determined ; still 

 another contained a small fragment of rotten wood. In 

 February, in a batch of large and otherwise good sized sprats, 

 every one seemed to have been feeding on whitebait, and so far 

 as could be made out from the partly digested material these 

 were clupeoids. We expected to find in some of the series ex- 

 amined minute shrimps, but if these were present they escaped 

 our observation. In the March specimens the food was doubtful, 



