cases totally blind, were captured through a succession of years about our house and grounds at Great Marlow. The greater number and the first of these blind mice were caught in the stable, which induces me to mention that an Icelandic pony of mine went blind, and to wonder whether the form of ophthalmia from which he suffered can have been contagious, and communicated itself to some of the mice, among whom it spread and continued rife for a good many years, though no horse or other domestic animal took it. I am however uncertain as to the year in which I first noticed these blind mice, and whether therefore it coincided with the going blind of the pony. A 'singing mouse' (always caused, I believe, by lung disease) was given me on 12 October 1889, by Mr. F. Rowe, jun., of Great Marlow, captured in his father's house if I remember right, at any rate locally. The ' singing,' which was very strong at first, gradually lost its fulness, and in the afternoon of 6 December the mouse died suddenly in a fit. In ten pregnant mice, obtained at various places in the south of the county, and all between January and May, but in different years, I found nine, seven (twice), six (four times), five, four and two foetuses, or an average litter of nearly six. One occa- sionally meets with examples abnormally dark, and occasionally one slightly lighter than usual, but I have never met with a really black or a white specimen in a wild state. Mrs. Raikes of Chandos Villa, Buck- ingham, informs me (in a letter, 9 May 1903) that she has seen in that neighbour- hood ' some of a cream colour.'
[Black Rat. Mus rattus, Linn.
I never heard of a black rat in Bucks, and it is probably a good many years since the last straggler in the county made way for the brown species. I have kept a few examples of the black rat in captivity, obtained elsewhere.]
25. Brown Rat. Mus decumanus, Pallas.
A plague in Bucks as everywhere else. I have no doubt that brown rats are far more numerous now than when I first made acquaintance with the species, as is only to be expected considering how prolific they are, and that man continues to exercise all his ingenuity and energy to encourage them by destroying all their natural enemies. It does not seem to be generally known that the adult buck rats live by themselves, and when one is captured in a mixed company it is only because he chanced to be at the moment visiting his harem. I knew several holes at Marlow which (when in use) would contain a single old buck, and no amount of ferreting or trapping could produce a second inhabitant. In perhaps a fortnight's time, after having forcibly removed the oc- cupant, the hole would be again used, and again proved to hold a single male rat, and so on, year after year. These buck habitations are much shorter and less complicated than the buries occupied by the does and young, which are frequently very extensive. Another point not, I think, generally known is that if several live rats are put together in a cage (the more the merrier) they settle quietly down after a very few minutes, and any one may put his hand in and pull the rats about without their attempting to bite. One day a friend sent me (at Marlow) about a score of live rats in a sack, which had just been caught while thrashing. I emptied the sack into a cage trap, and walked off with my prize, but the weight of so many rats was too much for the springs of the door, and it opened, letting them all escape in a moment. My dog killed one before I could stop him, but I recovered all the others alive single-handed. On one occasion a steel-trap which I had set over night in our house at Great Marlow was sprung, but contained only the severed foot of the rat. Two or three days after- wards, while looking for young sparrows among creepers on trellis-work on the house, I saw the large eye of something in a nest, and before I had time to get my hand there out jumped a large rat, which my dog stopped directly it reached the ground, and I found this was the owner of the severed foot, which in this freshly maimed condition had taken up its abode where it had to climb about I 1 feet up and down each time. In March 1893, at Great Marlow, one pregnant doe rat contained six foetuses ; two each con- tained seven, one contained eight, and one eleven ; quite a small doe at Poynetts (Ham- bleden), May 1 903, contained twelve, or an average of eight and a half young in a litter. I snared a buck rat which weighed lib., which is the heaviest weight I have person- ally proved, but I have handled many examples considerably larger and no doubt heavier. When brown rats are swimming in shallow water it is possible to pin them with the bifid end of a punt pole; and one can harpoon them with a boat-hook in any situation. Some years ago when on the river with two cousins (girls), I caught sight of a rat swimming in mid-river. Getting to the bow of the boat, and directing my cousins how to row, we presently, in spite of his many doublings and of the awkward trim of
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