The Roe is a good swimmer, and often crosses rivers, probably in order to get a change of food, though sometimes there is no reason apparent. On this point St. John tells us: "For some unknown reason, as they do it without apparent cause, such as being hard-hunted or driven by want of food, the Roe sometimes take it into their heads to swim across wide pieces of water, and even arms of the sea. I have known Roe caught by boatmen in the Cromarty Firth, swimming strongly across the entrance of the bay, and making good way against the current of the tide, which runs there with great rapidity. Higher up the same firth, too, Roe have been caught when in the act of crossing. When driven by hounds I have seen one cross Loch Ness."
The dentition is the same as that of the Fallow Deer.
LIZARDS AND SLOW-WORM
Common Lizard (Lacerta vivipara, Wagl.).
There are still two small groups of backboned animals to be described, representing the classes Reptilia and Batrachia. To the average man they are all Reptiles, and he has this justification for so regarding them—that until recently they were so classified by the great naturalists. Modern biologists, however, dealing with structure and organisation rather than with external form, find that this association of the scale-clad Lizards and Serpents with the soft-skinned Frogs, Toads, and Newts cannot be defended, and they have separated them into the two classes named. The reasons for this separation will become manifest in our descriptions of the several species, so that a preliminary dissertation on the subject is not necessary.
Sitting on a sunny, heather-clad hillside it will not be long, probably, before we see the active little Common Lizard peeping at us from under cover or leaping swiftly over the crowded plants. Its movements are so rapid that it is not at all easy to follow them in detail, or even to catch one for closer examination. It can run nimbly enough with a gliding motion, for the body and tail are scarcely lifted from the ground; but the principal mode of progression is to shoot forward horizontally from one tuft of herbage to the next. They run with as much facility over the shoots of heather or heath, and their long, delicate fingers and toes secure them as sure a landing as that of the Squirrel leaping from branch to branch. When we have hit upon a spot where we have seen several Lizards thus active, a good plan is to sit down quietly for a time, and keep our eyes on a patch of sand that is fully exposed to sunshine. In a little while a Lizard, maybe two or three Lizards, will appear from under the heather or other plants and bask in the sun.
So seen, we note that they are about five inches in length, which is only an average size. The maximum attained by males is six inches, and by females seven inches. The females are not merely longer, they are altogether of larger proportions; but the male is the more graceful of the two, his tail tapering gradually from the slender body to the very fine tip. Though the tail is in both sexes equal in length to the head and body, that of the female appears shorter owing to its sudden tapering beyond the thick basal portion.
The colour is some tint of brown, varying considerably in different individuals from yellow-grey to purple-brown, as a ground tint, upon which is laid variable dark spots forming more or less broken longitudinal lines. There is sometimes a blackish line or band following the course of the backbone to a little behind the hips, and a dark band along the sides edged with yellow. On the underside the males are orange or red, spotted with black; the females, orange, yellow, or pale greenish, with or without black spots, or a few small grey dots. They appear to moult, or "slough," in patches, though entire sloughs are found occasionally.