76 The Irish Naturalist. April, 



breed only once in their lifetime, and for that purpose they 

 must migrate to the sea. The yellow and silver eels are riOt 

 diiilinct forms, the former gradually assuming the silvery 

 tinge before descending to the sea. The eggs and earliest stages 

 of eels are still unknown ; certain flat, ribbon-like, transparent 

 creatures, however, appear towards spring in between 50 and 

 100 fathoms of water, and develop later on into young eels or 

 "Logues," as they are called in Ireland These ascend the 

 rivers chieflj^ in the spring and summer. It has been defi- 

 nitely ascertained that eels do not breed in the Baltic. They 

 have to go right out into the Atlantic to perform this im- 

 portant function. 



Two reports^ from the Fisheries Branch deal entirely with 

 the artificial propagation of the Salmon and Trout family, 

 statistical information about Salmon fisheries and kindred 

 matters. 



A long report by Mr. Farran ^ describes the Plaice-marking 

 experiments on the east coast of Ireland during the years 

 i(^05 and 1906. Hitherto all we knew about ihe migration of 

 such fish as plaice was founded on the opinion expressed by 

 fishermen from time to time. 



A very large number of plaice were carefully measured and 

 weighed, and then marked by means of vulcanite studs and 

 replaced in the sea. In this manner the size of many plaice 

 and their position in the sea at a certain time of 3'ear could be 

 ascertained. A careful watch w^as now^kept for all fish caught, 

 so that their migration and increase in size and weight could 

 be recorded by means of the marks which had been attached 

 to them. The results obtained so far indicate that nearly all 

 the marked fish have been taken comparativeh^ close to where 

 they have been released. Yet a few specimens have wandered 

 far away from their home. One plaice went from Dublin Bay 

 to Ballycotton Bay, and took sixteen and a half months to 

 accomplish this journey of 140 miles. 



TuNiCATA. — The Sea-squirts, or Ascidians, have been 

 very little studied in Ireland. The report ^^ by Mr. 



^ fisheries, helanJ, Sci. Invest., 1906, vii. [^Kpi] ; 1906, viii. [1908] ; 1907, ix. 



[1909 "•• 



9 P'arran, G. p.— Plaice-marking experiments on the east coast of Ire- 

 land in 1905 and 1906 Fisheries, Ireland, Sci. Invest., 1907. iii- L^909]- 



10 BuCHANAN-WoLLASTox, H. J. — Preliminary report on the Simple 

 Ascidians of the Larne district. Fisheries^ Ireland, Sci. Invest , 1902-03, iii- 

 [1907]. 



