The Rev. L. Jenyns on the Common Bat of Pennant, 167 



collecting, sometimes in prodigious quantities, wherever from 

 the falling out of the mortar they are enabled to insinuate their 

 bodies, and flocking thither, as well for the purpose of conceal- 

 ment during the day-time in the summer months, as for that of 

 undergoing those more profound slumbers which are occasion- 

 ally superinduced b}^ the severities of winter. 



Again : It is a common remark, that the brumal torpidity of 

 the Bat is liable to be broken through by a sudden increase of 

 temperature, and that these animals appear abroad at all seasons 

 of the year, if the thermometer be above 44° : but as far as my 

 observation goes, this takes place much more frequently at the 

 commencement of winter than towards its conclusion ; and it 

 would seem to me, that though it requires a very reduced tempe- 

 rature, — probably one inch below freezing point, — to throw them 

 into a state of complete torpidit}^, yet that when this has fairly 

 taken place, one, much higher than would have proved suffi- 

 cient to have put them on wing before its commencement, is 

 necessary to awaken them from their slumbers. Accordingl}^, 

 we find the Bat showing itself every evening throughout the 

 months of November and December, if the weather be mild and 

 open, and I have even noticed it flying with its usual activity 

 when the thermometer has been down at 38° ; and this will often 

 continue to be the case till the setting-in of those severe frosts 

 which usually occur soon after the commencement of the new 

 year : but after the force of the winter has begun to abate, I have 

 in vain looked for the Bat on wins; till the beginning or near the 

 middle of March, notwithstanding the temperature has often 

 risen considerably above 50° of Fahrenheit 



It is also worthy of note, that the whole of the above obser- 

 vation applies only to the species under consideration. The 

 Nodule and the Long-eared Bat show themselves for a longer or 

 shorter period during the summer months, according to circum- 



voL. XVI. z stances ; 



