308 THE ZOOLOGIST. 



the fishing — quite an inappreciable amount, in fact. Of course they feed 

 principally on fish ; but I think the keenest angler must be very small- 

 minded indeed who believes that there are not plenty of coarse fish for all 

 the two-legged and four-legged anglers as well, without their interfering with 

 each others sport. A more serious charge, however, and the only one, 

 I fancy, that real sportsmen prefer against them, is that they have been 

 known to take large trout off the spawning-beds. This charge has been 

 unquestionably much exaggerated; the few instances where a trout has 

 been found partly eaten by an Otter have been so continually talked of that 

 everyone has come unconsciously to consider it as almost a common occur- 

 rence. The remains of a large trout, partially eaten by an Otter, were 

 brought to me here some few years ago. It was a foul, lanky old kelt — 

 that is, a spent fish, with a hide like boot-leather, and if not already dead, 

 was probably in extremis when the Otter took it from the water. No doubt 

 a few other persons could tell us of similar instances. In all probability 

 all, or nearly all, of these few trout so captured by Otters were spent fish — 

 old kelts (kippers or baggits), who had safely stowed some 10,000 or more 

 eggs on the river's bottom, and would in many cases have died even if an 

 Otter had not 'saved them the trouble.' The Otters probably did actual 

 good in removing them, for it is difficult to conceive how many thousands 

 of the embryo trout would have been poisoned by the decayed matter 

 exuding from the decomposing body of even one big fish dying right on the 

 spaw ? ning-bed. Again, probably very few of your readers are aware how 

 prevalent the Salmon-disease is in the Thames, although, owing to Barking 

 Creek and other pollutions, there are now no Salmon to be affected by it. 

 I have a return, given me some years ago by the late Frank Buckland, 

 showing the number of Salmon caught hereabouts during the last twenty 

 years in which any found their way up, which I will gladly publish in a 

 future number, if of general interest. The Salmon-disease is caused by, 

 and consists in, a fungus, called Saprolegnia ferax, and in the spring months 

 of some years — possibly every year — some species of the coarse fish die in 

 large numbers from its attacks. This fungus spreads with marvellous ease 

 (I learnt a little about it by keeping and observing fish in aquaria) ; and 

 until that happy day arrives — it seems far enough off at present — when 

 Thames water shall again be as pure, and as free from all pollutions, as it 

 was in primeval times, I can think of no means so effectual for checking 

 the spread of this most fatal fungus as to encourage, by every possible 

 means, the few Otters remaining along the river side, who unquestionably 

 remove a large number of these diseased (and highly contagious) fish from 

 the river on account of their being so easy of capture. As an ounce of 

 fact is worth pounds of theory, I may mention that J have never found an 

 Otter make any objection to eating a fish affected with the disease, nor have 

 I ever found one any the worse for doing so. But, after all, anglers are 



