262 PROCEEDINGS OF THE 



tudes of temperature'? Our ignorance of these matters is still 

 profound. 



d. Enumerate the Enemies to Fish Eggs. Do they consume them, 

 injure them, poison them (as in the case of pollution)'? Do injuries 

 to the embryo, or accidents at the time of fecundation, have any 

 effects, and, if so, what are they 1 ? — During the past year or two I 

 have collected a good many deformed trout, keeping them in 

 spirits. In one loch in Islay occur the deformed trout usually 

 known as tailless trout of Islay. All the trout in this loch possess 

 this peculiarity, which is simply an anchylosing or welding together 

 of the tail-rays, and has been anatomically treated of by Dr. 

 Traquair of Edinburgh.'"' In another loch, in Kirkcudbright, 

 exactly the same deformity occurs. Both these lochs are about 

 1600 feet above the sea, and cannot be subject to any pollution. 

 In a stream in Lanarkshire again, the same deformity occurs, and is 

 extended to the back fin. This stream runs directly from numer- 

 ous lead mines, and the trout grow fat and rich in flavour. This 

 is suggestive of arsenic poisoning. In the river Carron this 

 deformity has begun to appear — or a modified form of it — within 

 the last few years, or if it existed prior to this has only lately 

 assumed noticeable proportions. The Carron is much polluted by 

 paper mill refuse — esparto grass, and chemicals. 



e. Is the Distribution of Fish affected by mammals or birds carry- 

 ing fertilised ova from one locality to another 1 — Thus a trout 

 might swallow fertilized salmon or trout eggs, and a bird of prey 

 might catch this trout and carry it to some secluded tarn, loch, or 

 stream, to prey upon it ; and if the fertilized ova fell into the 

 water, might not the young fish be born and populate the water 

 previously barren 1 So, perhaps, might ova be carried in the fur of 

 water-animals. May not the land-locked true salmon found in 

 certain lochs of New Brunswick — Salmo gloveri — have been thus 

 introduced 1 In this place I may instance the very rapid increase 

 that is possible in lochs and streams which have become stocked 

 with trout for the first time, having had considerable experience of 

 this, by personal experiments in Sutherland. In 1878 our angling- 

 party stocked a chain of barren lochs with about 6 or 8 dozen small 

 burn trout. The following year the burn connecting these lochs 

 swarmed with the fry. Trout grew from \ lb. to 1 lb. the first 



* Proc. Royal Phys. Soc. Edin, 





