78 Proceedings of the Royal Physical Society. 



limbs of the same side, and of a limb on the left side, as all 

 appearing perfect on exuviation. This points to the period 

 of moulting as that at which, in the case of the shore crab, 

 the reproduction of lost parts generally takes place ; and, not 

 unlikely, the origin of these abnormal conditions of limbs 

 will be found connected with injuries to the chitinous 

 covering, which is soft and tender at this stage of growth. 

 It is worthy of notice that such injuries occur for the most 

 part at the left side. Of thirty specimens of Carcimis mmnas 

 of different sizes, examined by me last August, seven were 

 less or more mutilated on the left side and only one on the 

 right. 



VI. On Whitehait By J. C. EwAET, Esq., M.D., Professor 

 of Natural History, University of Edinburgh. 



(Read 17th February 1886.) 



The question " What are whitebait ? " has been again and 

 again asked, but a complete and satisfactory answer has 

 never been given. Since the funeral feast of the founder of 

 the Charter-house in 1612, when six dishes of "whitebait" 

 appeared on the table, the nature of whitebait has been often 

 considered. Yarrell and Valenciennes were inclined to be- 

 lieve that the whitebait was a distinct species of the herring 

 family, Yarrell giving it the name of Cluyea alba, while 

 Valenciennes created for it the genus Rogenia. Pennant 

 thought they might be young bleak, while Donovan asserted 

 they were young shad. Gunther has described whitebait as 

 young herring, and Day (" British Fishes "), after examining 

 several samples, arrived at the conclusion " that both sprats 

 and young herrings find their way into the London market 

 as whitebait." Day found that out of 138 whitebait cap- 

 tured in the Thames during May and June, about 90 per 

 cent, were herring, and 10 per cent, sprats. In August, out 

 of forty-six examples, twenty-one were herring and twenty- 

 four were sprats, while October whitebait contained only 

 young herring. From these inquiries it follows that white- 



