98 



The Irish Naturalist, 



May, 



practically invisible, and even the Hairy-armed Bat — our largest 

 Irish species — extremely difficult to distinguish against the 

 trunk of a tree. Therefore, it was a nice lazy plan to assume 

 that what was true of the Noctule was probably true of most 

 other sorts of Bats ; and that is what, up to the present time, 

 most English naturalists have done. I am sorry to say that 

 a peculiarly unfortunate example in that respect seems to me 

 to have been set by that very high authority, Dr. Dobson, who 

 lays it down as a general law in his " Catalogue of Chiroptera " 

 (p. xvii., footnote) that " Bats without nasal appendages are 

 more properly crepuscular and matutinal than nocturnal in 

 their habits." For this sweeping statement I am afraid Dr. 

 Dobson had no better warrant than conjecture. If it were 

 strictly true only one Irish Bat, the Lesser Horse-shoe, found 

 in a few of our western counties, would be entitled to be called 

 nocturnal. Dr. Dobson doubtless drew the line where he did 

 from an idea that those nasal appendages which adorn the 

 Horse-shoe Bats, and which are known to be extremely 

 sensitive, were of use instead of eyes when it got too dark to 

 see, and that Bats destitute of them would be unable to get 

 on without a good deal more light. However, the same could 

 evidently be suggested about the enormous sensitive ears 

 possessed by the Long-eared Bat, and so, we find, it has been 

 suggested about that species in BelFs "British Quadrupeds" 

 (2nd edition), where the author lays it down that the Long- 

 eared Bat probably flies all night, while the other common 

 kinds have, he believes, to retire early, in consequence of their 

 wint of any corresponding special equipment. Of late there 

 have been several rather imposing books on British Mammals 

 produced, in which I can only say the subject is no further 

 advanced. The latest and most expensive is that of Mr. J. G. 

 Millais,^ of which the first volume appeared last November, and 

 which affords a very fair sample of the way Dr. Dobson's guess 

 has influenced scientific thought — or, at least, the thoughts of 

 scientific persons — on the subject of the habits of Bats. Treat- 

 ing of our very commonest Bat, the Pipistrelle, Mr. Millais 

 admits that little or next to nothing is actually known about 

 the duration of its flight ; but he adds that he has " no reason 



"The Mammals of Great Britain and Ireland." 



