SLOB-TROUT 141 



the rule is, as we have seen, that the trout in 

 the shallow, rocky streams at the head of the 

 river, are small ; those in the middle sections 

 larger ; and towards the mouth, where the 

 water runs deep and meets the tide, the 

 heaviest fish, known as " slob " trout, are 

 found. These slob-trout, as the name suggests, 

 are in the habit of moving up and down with 

 the tide, and so get accustomed to the brackish 

 water ; a plunge into the sea, therefore, would 

 not greatly affect them. It is conceivable 

 that during heavy floods in the past, as even 

 now may be the case, some of these fish would 

 be carried beyond the influence of the estuary. 

 Presuming this to have been the case, the 

 castaways, finding themselves in the midst of 

 plenty, would have no occasion to return at 

 once to the tide-way. In the meantime they 

 would become acclimatized to the changed 

 conditions, the result being gradual differenti- 

 ation of form and character, ultimating in — 



(i) the species we recognize as Sea or 



White-Trout ; and 

 (2) the Salmon. 



Proof of the near relationship between sal- 

 mon and trout is the fact that ova taken from 

 a 20 lb. salmon can be fertilized by milt from 

 a trout of a few ounces, a cross which naturally 



