of the Fishery Board for Scotland. 



189 



same as I had previously seen in the plaice (Guinardia flaccida). The 

 contents consisted of remains of minute larval crustaceans, and small 

 larval Scrobicularia were occasionally seen ; as an exception, I found a 

 well-preserved infusorian. 



In his elaborate paper on forms of post-larval turbot that were obtained 

 from the sea, Ehrenbaum mentions that he found remains of Ostracoda in 

 a still symmetric specimen. Though feeding so much, all the larvae died on 

 the fourth day, apparently as a consequence of excessive heat ; in the 

 afternoon the thermometer showed 17 "5° C. in the rearing-jar. At this 

 stage the larvae measured 7*1 mm. in length. The pigmentation had 

 altered in this way, that the brick-red colour was partly covered with 

 black stellate pigment, which had also spread over the seams of the 

 embryonic fins, particularly dorsally and partly on the caudal fin. The tail 

 was still homocerc, and no changes in development were observed from 

 the end of the larval stage. 



Along with the turbot, a few larval lemon soles were also placed in the 

 rearing-jar. They did not appear so hardy as the former, but had more 

 features in common with the plaice. When the yolk was absorbed, the 

 soles began to feed on larval crustaceans, and larval molluscs, larval 

 gastropods were particularly frequent. The soles died at the same time 

 as the turbot, and were then eleven days old. An increase in the black 

 pigmentation was the most marked change during these first days of the 

 post-larval stage. 



These experiments with turbot and lemon sole were the first attempts 

 to rear these forms, and I hope in the near future to have an opportunity 

 of repeating those interesting, and from a practical point of view, must 

 important experiments. 



The experiments described in the preceding pages will show that the 

 rearing of plaice through the post-larval stages is possible, and can be 

 done in laboratories without much trouble or expenditure ; and though 

 we often find that the various species behave differently when artificially 

 dealt with, there is no reason to think that experiments with other forms 

 of our common food-fishes should not be equally successful. There may, 

 of course, be peculiarities in different ways that are to be overcome in 

 each case, but these can only be found out through practical experi- 

 ments. And if this is so, the study of this now most unknown stage of 

 development of our sea-fishes will get a push forward, as the investigator 

 will be able to work with certainty and convenience, where he previously 

 was often left in the dark. 



But the rearing, as mentioned, is also of interest from a practical point 

 of view ; and it may be of interest to deal here also with this aspect of 

 the experiments and observations already described. 



The practical rearing of larval fish is closely related to artificial sea- 

 fish culture, and I shall therefore first mention a few features connected 

 with the latter. Fish-hatching has been proposed as one of the remedies 

 to restore the abundance of the most valuable fishes on the inshore 

 grounds, and work of this nature has lately been undertaken in various 

 countries : in Norway, where cod has principally been dealt with,* in New- 

 foundland, in the United States, and in Canada. At the present time 

 similar works are prepared for in Italy, and in France at St Yaast le 

 Hougue, and in England by the Lancashire Sea Fisheries Committee. 

 It is satisfactory to see how artificial fish-culture has gradually de- 

 veloped, as work on a sufficiently large scale has given some idea of 



* As a consequence of the success of the work with the cod in previous years, it 

 has lately been suggested to introduce valuable ilat-iishes in Norway by means 

 artificial culture, 



