298 MTJRID^E. 



devastations of the Mouse are most extensively felt. 

 Multiplying in hosts, and safe from injury, they drill the 

 whole interior of the wheat-rick, forming a labyrinth of 

 its runs, and occasionally, perhaps assisted by the Harvest 

 Mouse and the Field Mouse, make incalculable havoc 

 amongst the grain. In the demolition of a single rick, 

 several bushels of Mice have been destroyed, besides the 

 numbers which must have escaped. 



Their rate of increase will be evident from the fact 

 that hundreds of Mice are sometimes found in a single 

 rick, varying in some respects from ordinary examples. 

 We remember on one occasion seeing great numbers 

 killed in a wheat-rick at Welford-on-Avon, which were 

 of a light grey colour, without the least mixture of 

 brown. This rick, as far as our memory will serve us, 

 had been standing for two years, and we entertained but 

 little doubt that during that period one pair of Mice had 

 produced the whole number, since, had the rick been 

 frequented in the first instance by a greater number, some 

 of them would doubtless have been ordinary brown Mice, 

 and their progeny of the same colour. We have met 

 with a similar instance in a wheat-stack at Welford Hill, 

 but in this case all the Mice were of an unusually dark 

 colour, especially along the dorsal line, which was nearly 

 black. 



But its astonishing multiplication may be more fully 

 imagined from the following experiment of the great father 

 of natural history : " Having," says Aristotle, " placed 

 a pregnant female of the Common Mouse in a closed 

 vessel filled with grain, I found, after a short period, no 

 less than a hundred and twenty Mice, all sprung from 

 that single parent." This astonishing increase is easily 

 accounted for. The Mouse breeds indifferently at all 

 seasons, and several times in the course of the year, pro- 



