8 THE ZOOLOGIST. 



is said that Black Rats " seem to have increased much lately.' 

 In our opinion Mus hibernicus* is not decreasing in Ireland, 

 as a whole, though it is possible that in single localities it may 

 sometimes become extinct or lost sight of. Wherever it has once 

 occurred, there, we think, it will probably always be found, though, 

 as has been shown, its numbers may vary considerably. 



The following note, by the Rev. P. A. Keatinge, of Athlone, 

 appeared in * The Field' in 1883. It gives a very good account 

 of a peculiar and, as yet, unexplained phenomenon in the history 

 of the Irish Black Rat : — 



" Black Rat in Co. Wexford. — During a short visit to Co. Wexford, 

 early last October, I was informed that a large colony of Black Rats had 

 suddenly put in an appearance in that county, f I repaired with a friend 

 to the locality, with no small degree of curiosity. We quietly entered a 

 field of oaten stubble, in which some stacks of corn were yet standing. 

 About fifteen yards from these stacks ran a dyke separating the field from 

 the adjoining farm. In this dyke, which was regularly honeycombed with 

 them, the strange visitors had taken up their abode. In less than an hour 

 I counted over forty of them running out and in from burrow to stubble. 

 Where they came from so suddenly, and in such numbers, is a mystery to 

 me, as I have been intimately acquainted with the place for over thirty 

 years, and a Black Rat was never heard of in the locality ; in fact, the 

 country folk viewed them with serious apprehension of some pending 

 calamity. I secured two with the gun, and am having the skins dressed 

 for a tobacco-pouch, as the fur is remarkably soft and silky." 



We cannot, at present, offer any explanation of the above 

 phenomenon; but we may state that similar occurrences have 

 been reported from other localities. 



In conclusion, we must offer our hearty thanks to all those 

 whose names are mentioned as having assisted us in this enquiry, 

 as well as to many others who have taken considerable trouble to 

 help us, and whose names are too numerous to mention. We 

 must therefore content ourselves with expressing our obligation 

 to them collectively. 



It is hoped that this paper will stimulate Irish naturalists to 

 study such an interesting, yet neglected, creature as Mus 

 hibernicm. We shall always be most happy to receive com- 



* Owing to a confusion with Mus rattus, Mus hibernicus is often 

 described as a decreasing species in Ireland. 

 f In the parish of Dennistown. 



