34 EEPRODUCTION AND DEVELOPMENT OF THE CONGER. 



that the fasting period is devoted not so much to the increase in 

 size of the few large eggs in the ovary, as to the development of 

 the vast numbers of very young eggs which the immature ovary 

 contains. 



It was erroneously stated recently in Nature'^ that a German 

 naturalist had obtained a conger at Zanzibar containing eggs which 

 were 2'5 mm. in diameter. I found that this statement was founded 

 on a short paper published in the Zoologischer Anzeiger, 1890, 

 p. 314, by a Dr. Voeltzkow, describing a gravid specimen, not of 

 Conger, but of some species of Mursena. This specimen contained 

 eggs which were 2*5 mm. in diameter and transparent. But the 

 writer in Nature had misquoted the paper to which he alluded, 

 and had written Conger instead of Mursena. The specimen of 

 Mursena in question was probably more advanced towards sexual 

 maturity than any conger yet described, because its eggs were trans- 

 parent, and escaped on slight pressure from the genital aperture. 

 But I have not been able to find any description of a female conger 

 containing eggs larger than those described by me in this paper. 



IV. The Eggs of the Conger after Deposition. 



My own work has been confined to the study of the adult conger, 

 my efforts having been dh-ected towards the elucidation of the re- 

 production as the most satisfactory foundation for a future investi- 

 gation of the development of the fish from the eggs. But there 

 are a number of facts and probabilities concerning sundry stages of 

 the development of the conger which have resulted from occasional 

 observations made from time to time by other naturalists, and I 

 think it will increase the interest of this paper if I add here a brief 

 review of these. 



To take the stages in order, we will begin with what is known of the 

 eggs of the conger after they have been deposited by the female and 

 been fertilised. No such developing eggs have yet been identified with 

 certainty. It seems probable in the first place that the eggs are pelagic, 

 that is buoyant and transparent, and each suspended separately and 

 freely during development in the sea-water. One reason for sup- 

 posing this is that eggs of the vast majority of truly marine fishes 

 are pelagic. The eggs I have seen in gravid female conger are quite 

 opaque and not buoyant ; but these were not perfectly ripe, and it is 

 usually the case that pelagic eggs in the ovar}^ are opaque and heavier 

 than sea-water up to the very last period of their maturation. In 

 fact the eggs in an ovary [e. g. that of the sole) ripen in succession, 

 * See Nature, vol. xlii, p. 654, 1890. 



