140 TRANSACl^IONS, NATURAL HISTORY SOCIETY OF GLASGOW. 



Although these little fishes are not supposed to be 

 other than shore-frequenters, we are disposed to give 

 them credit for greater courage in exploring the 

 deeper waters than is ordinarily accorded them. 

 Dr. Day, quoting Mr. Dunn, says ; " I have a Butterfish, 

 Couch, caught near the surface of the sea in a 

 pilchard net, three miles from land, in 35 fathoms 

 of water." I have shot a " dooker," Uria grijlle, with 

 a Butterfish in its hill over ten fathoms, and taken 

 them in the dredge at various depths from seven ta 

 twelve. Being a strong fish, well-boned, there i» 

 nothing to hinder it going where it i^leases ; and 

 although it possesses not the swimming i)owers of 

 many smaller fishes, it yet progresses with great 

 ease and facility in plenty of water, and in a 

 manner scarcely to be expected from its sputtering 

 habits in confined i)ools. The umbilical sac, where the 

 young are incubated, is smaller in this fish — it 

 ai)pears to me — than in many other species, and 

 although I cannot absolutely say what time is required 

 for incubation and subsequent absorption of the sac, 

 — owing to the difficulties arising from varying* 

 temi)eratures — 1 am disposed to consider a fortnight 

 sufficient to cover both periods, and to suffice to 

 send the young Butterfish out dependent on its own 

 unaided efforts.* 



When we consider the facility for obtaining the 

 species, no one of the domestic fishes gives better 

 promise of easy study. I hope many will capture 

 both parents and their ova, and add to our know- 

 ledge of their very interesting habits. 



* Since the above was written I have incubated ova, and kept the young for 

 twenty days, at the end of which time ihe umbilical sac was about absorbed. 

 Allowing for the altered conditions and defective aeration, their growth is- 

 evidently slower thin I calculated. 



