88 THE REPRODUCTIVE MATURITY OF THE COMMON EEL. 



Fig. 1 represents accurately the appearance of the second specimen 

 when mounted, the abdomen having been opened in the mid-ventral 

 line. The figure is printed from a block prepared for the Field, and lent 

 to me by the kindness of W. B. Tegetmeier, Esq. 



The time of year at which these specimens were obtained agrees with 

 the conclusion drawn from other evidence, that eels spawn in autumn 

 or winter, and serves to determine the actual fact that some eels are on 

 the point of spawning at the end of September and beginning of 

 January. The equally important question of the place of their capture 

 has next to be considered. Mr. Buckeridge, who very kindly answered 

 the enquiries I made to him on the matter, told me that both specimens 

 were found among consignments of eels from Toom Bridge, in Ireland. 

 Now Toom Bridge is at the point where the river Bann leaves Lough 

 Neagh, and is about 26 geographical miles from the sea. It is certainly 

 an extraordinary fact that an eel so near the ripe condition should be 

 found in fresh-water. We can only suppose that the case is exceptional. 

 There is a possibility that the specimen had been kept in captivity for 

 some time after being caught, and that thus its ovaries had had time to 

 develop. But, on the other hand, when eels have been kept in salt- 

 water aquaria, as they have been at the Plymouth Laboratory, in order 

 that ripe specimens might be obtained, the ovaries have not developed 

 to any obvious degree. 



liathke's specimen is described in Mutter's Archiv. fiir Anat. 

 Physiol. &c. 1850. It was brought to him, presumably in Berlin, 

 by a fisherman on May 24th. It was dead, but in fresh condition. 

 Nothing is stated concerning its place of capture. The ovary was 

 1| in. wide in its middle part. The fat, which in ordinary eels is 

 abundant between the eggs, was almost entirely absent. The importance 

 of the condition of this specimen to Eathke's mind was the evidence it 

 supplied that the eel was oviparous, and not viviparous. 



It would appear that in addition to Eathke's specimen and the two 

 here described, only one other nearly ripe female eel has been recorded. 

 This fourth specimen is that mentioned by Calderwood, in a note in the 

 Ann. and Mag. Nat. Hist. (6), vol. xii. 1893. But the description given 

 is very scanty. The specimen was 29 i in. long, and was captured on 

 December 27, 12 miles south of the Eddystone Lighthouse, or 20 miles 

 from Eame Head, the nearest point of land. The width of the ovary 

 and the size of the eggs are not mentioned. All that is stated is that 

 the ovaries corresponded exactly in appearance with those figured and 

 described by Brock in 1881, but Brock did not mention a ripe specimen. 

 The ova are said to have been apparently ready to drop from the surface 

 of the ovary, and to have been richly stored with oil globules. 



