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.