370 Mr. E. W. L. Holt on the 



postlarval condition is reached. The month is from the first 

 widely open and the ejes a brilliant silvery blue, the newly 

 hatched herring being thus in advance of its ally the sprat. 



For the first few days of its life the herring is unable to 

 rise from the bottom, lying on its side and occasionally lashing 

 out with its tail ; and even when able to rise it seems to keep 

 near the bottom for some time, larval and early postlarval 

 forms being taken together in great alnmdance in the bottom 

 trawl-net used at this laboratory on the 30th March, 1889. 

 The postlarval herring is very voracious, not disdaining 

 cannibalism, whilst it is preyed on doubtless by larger fishes. 

 The growth of the herring is at first slow, there being an 

 increase of about gV inch in the first ten days of free life. 



Becoming more vigorous, the postlarval herrings ascend 

 into midwater ; specimens (fig. 2) yV i^ch long were taken 



with the midwatcr-net on March 22, 1889, being thus aomc- 

 wliat earlier tlian their fellows. 



At this length the permanent dorsal finis clearly indicated, 

 the cartilages of the hyoid and brancliial arches are well 

 developed, the pectoral fins aie pediculate, the tail shows an 

 indication of the heterocercal condition. The continuous 

 embryonic (median) fin is still retained ; the maxillteare well 

 developed, and bear sharp-pointed teeth on their anterior 

 edges. 



On April 14, 1889, llie herrings were still in midwater, a 

 little over half an inch in length ; the embryonic median fin 

 was nearly or quite lost, and the hypural elements of the tail 

 were well marked. 



Pigmentation * other than that of the eyes appears before 

 the postlarval condition is reached and is retained unchanged 

 lb]- a considerable period. It is entirely black, and consists 

 of one or two median chromatophorcs below the heart, a chain 

 of about ten chromatophorcs commenciug beliind each pectoral 

 fin and running backwards on each side of the gut for about 

 half its length ; an irregular, sometimes double, chain ventral 

 to the posterior half of the gut ; two (sometimes one) stellate 



* Cf. Prof. M'Intosh and E. E. Prince, "Development and Life- 

 liistones of Food-iisb," Trans. 11. S. E. vol. xxxv. 



