46 THE MAMMALS, REPTILES, AND FISHES OF ESSEX. 



their habits. I have heard from an elderly friend that on 

 one occasion, when the ground was completely covered with 

 snow, he tracked an otter for some miles, upon its passage 

 from pond to pond. This distance it had travelled during 

 the night. The district was Dengie Hundred, and the time 

 that when ponds containing fish, or at all events eels, were 

 much more abundant than now. As is well known, almost 

 every field formerly had its clay-pit or pond, now drained and 

 filled up in consequence of changes in agriculture. 



A very interesting article * has been published by Mr. 

 John Watson, on the food of the Otter. The author 

 clearly shows that, as the dietary of this animal is extremely 

 comprehensive, its depredations upon the stock of fish 

 contained in our rivers cannot really be serious. 



Genus MUSTELA, Linn. 



Mustela vulgaris, Erxkben. COMMON WEASEL. 



In spite of persecution, this small animal is common in all 

 parts of Essex, and especially on the marshes, where I have 

 found abundant evidence in casts that it not unfrequently 

 forms the food of Herons. 



The Weasel may be distinguished at a glance from the Stoat 

 by the colour of its tail, which is of the same reddish- 

 brown tint as the upper surface of its body. An additional 

 distinction may be usually found in the smaller size of the 

 Weasel. This character, however, is not immutable, as I have 

 seen Weasels quite as large as an average Stoat, and full-grown 

 Stoats as small as under-sized Weasels. 



This 'is another of the so-called " vermin," and is ruth- 

 lessly destroyed whenever it is found. This, in my opinion, 

 is a great mistake, since its prey consists chiefly of the smaller 



* "Water Poachers," Nineteenth Centurv, Oct. 1889; cf. Essex Nat vol iv 

 p. 84. 



