of the Fishery Board for Scotland. 



357 



such temperature on the ova were communicated to 1 Nature'' in June 

 (1886). 



The first pelagic ova, viz., those of the haddock, made their appearance 

 during the very cold weather in the beginning of February, and were 

 followed somewhat later by the ova of the cod and common flounder. 

 Moreover, for the first time, the ova of the ling were examined, and the 

 development studied to a fairly advanced stage in the Laboratory. These 

 ova were procured by a long-line fisherman of Cellardyke (who with 

 others was supplied with suitable earthenware jars, and encouraged by a 

 visit to the Laboratory), fertilised about 100 miles off the Island of May, 

 and received safe at St Andrews after a considerable land-journey. 

 The fertilised ova of the plaice and lemon-dab were similarly brought by 

 Captain Burn, late of the Hussars, from the Moray Firth, for the Labora- 

 tory had then no boat suited for securing a supply nearer home. No fish, 

 however, has been more useful this year to the workers than the common 

 or grey gurnard, the spawning season of which seems to have been some- 

 what later than usual. The first ova were procured about the middle of 

 May, and the embryo of the last series lived till late in August. Further 

 observations were also made on the ova and young of the lumpsucker, 

 Montagu's sucker, shanny, stickleback, sand-eel, Coitus, &c. 



These researches on the development of the food-fishes will form a 

 considerable Fasciculus (quarto), with about thirty plates, and are now 

 almost ready for publication. The great expenditure of time in preparing 

 the eggs and embryos for section, in making the sections by aid of the Cald- 

 well and the Eocking microtomes, and the mounting of the preparations 

 thereafter, is much greater than at first sight appears. This labour was 

 undertaken and carried out in a most praiseworthy manner by Mr E. E. 

 Prince, who, throughout has specially devoted his energies to Teleostean 

 embryology. Towards the end of the season he was to some extent 

 assisted in the preparations of the catfish and salmon by Dr Scharff and 

 Mr John Wilson, but the brunt of the labour was borne by himself. 



From the beginning of June to the end of September Dr ScharfF 

 devoted himself to the investigation of the intra-ovarian eggs of a number 

 of Teleosteans — chiefly food-fishes. Amongst those examined were the 

 grey gurnard, green cod, bib, whiting, cat-fish, conger, shanny, frog-fish, 

 and salmon. In this connection it is remarkable, as indeed was men- 

 tioned in a former report, how difficult it now is to secure specimens of 

 the shanny at St Andrews. Only after considerable efforts was an adult 

 female procured having ova approaching maturity. Yet the young 

 shannies abound in the rock-pools in autumn and winter. Dr ScharfFs 

 examination of the specimen just mentioned, however, showed that the 

 ovarian eggs were of a most interesting type. Most of the specimens 

 reserved for section-cutting by Dr Scharff were treated either with picro- 

 sulphuric or weak chromic acid. Special attention was paid to the 

 structural changes in the growing nucleus, as well as the origin and 

 development of the yolk, and interesting and important results were 

 obtained. The3e were lately communicated by Dr Scharff to the Royal 

 Society in a paper illustrated by a series of beautiful figures. 



During the summer Mr Wilson continued his researches on the develop- 

 ment of the common mussel, and these he carried out in the same skilful 

 and persevering manner as formerly. He added considerably to the infor- 

 mation gained last year, and the life-history of this form is now nearly 

 complete. His memoir, illustrated by a series of carefully-drawn figures, 

 is now almost ready for publication. A summary of his investigations 

 is appended ; — 



