[ - ] 



Report on the Spawning of the Common Sole (Solea 

 vulgaris) in' the Aquarium of the Marine Biological 

 Association's Laboratory at Plymouth, during April 

 and May, 1895, 



With i^feliminary remarks on some of the morphological conclusions that 

 may he draivn from the study of the early emhryological history of 

 this form. 



By 



Gerard W. Butler, B.A. 



I. Introductoky. 



From April 3rd to May 17th of this year I occupied a table at the 

 Plymouth Laboratory, to study the embryology of Teleosteans. As 

 some of the fish in the flat-fish tank were known to be spawning, a net 

 was fitted to the overflow channel into the adjoining tank. By the kind 

 permission of the Director I examined this net daily, and, as a rule, a 

 number of times a day, so that I obtained a pretty complete record of 

 the spawning of the fish in this tank during the period mentioned. 



Four or more species spawned during this period,* but the point most 

 worthy of record is the breeding for the first time in the Plymouth 

 Aquarium, and perhaps for the first time in captivity, of the common 

 sole. 



* Fertilized eggs of the Plaice {PI. platcssa) 2 mui. iu diameter were obtained on April 

 2nd, 4th, 7th, ISth, and some of these hatched out in 10-12 days. Eggs about 1'5 mm. 

 in diameter, ai)parently those of the "Jlerrysolo" {PL viicroccjyhalus) were obtained 

 unfertilized on April 19th, and fertilized on the nights of May .0th, 8th, and 10th. Some 

 of these hatched out on the 5th day, the water temperature being 13° C. Smaller eggs, 

 also without oil globule, varying in diameter from '98 mm. to I 15 mm., and thus answering 

 to the unfertilized eggs of the flounder obtained from ditl'erent fish, but possibly including 

 eggs of some other flat-fish besides PL Jlcs-n/i, were obtained repeatedly during April and first 

 half of May, but only one or two fertilized eggs were seen. Attempts to artificially fertilize 

 flounder eggs resulted in nothing beyond the irregular segmentation of some of the eggs. 

 Probably this was due to the only male available not being in i)ro[>er condition. 



n 2 



