Age of Mussel Brood. 199 



weather remain favourable. If it should be cold and wet less 

 food is about, and the mussels then thrive more slowly. 



The result of search for young, shelled, fixed spat from May 

 till end of June has been rewarded in finding plenty in the 

 Hadleigh Bay layings (both among those mussels that have 

 been there from spring-time and fresh lots brought in summer 

 from the Kentish Flats) as well as those free-growing ones 

 fixed on the Southend Pier piles. These tiny mussels are 

 found among the entanglements of the foot-web or byssus of 

 the adult forms. Some on the broken shells and weeds are 

 inextricably bound up with the mussel lumps. Their size 

 has ranged from -^ to T V (transparent pin heads) to J or 

 \ an inch in length like to a bean in appearance. Others of 

 larger size are likewise got on the stones or attached to the 

 oysters or to the boats' bottoms. The very smallest are 

 undoubtedly summer spawn, but those of longer dimensions 

 may be the spring or the previous year's brood ? This seems 

 simple and, so far, clear, if there is only a single summer 

 spawning. But a complication arises, and leads us to think 

 that a moderate percentage of mussels breed much earlier, and 

 even a few others possibly later than the period given above. 



Our attention was called to this in finding in the beginning 

 of April among the Southend natural colonies at the Pier-head, 

 young mussels as diminutive as any of the above-mentioned 

 midsummer series. There was also quite a consecutive series 

 in sizes. Their age might be therefore several weeks and 

 some as many months old. Now this tallies very well with 

 Mclntosh's* observations at St. Andrews, where sexual maturity 

 is arrived at in April ; by May and early June ova fast 

 diminishing and in July spent. He assumes the brood of May- 

 end (| inch long) are early year products or slow growths from 

 the year before. His later report on Tees (N.E. Sea Fish. 

 Distr.j mussels, already cited, sustains his previous conclusions 

 above enunciated. 



* Ann. and Mag. Nat. Hist., February, 1885. 



