sloughs, I have rarely come across a whole one. My own conclusion is, that in the wild state the casting of the slough whole or entire is largely a matter of accident. A very favourite method of divesting itself of the slough in the case of the ring snake is to climb into a shrub about a foot or so from the ground. The blackthorn is much used in this way where it grows. Wedging itself between two branches, the snake then begins a process of wriggling, and in a few minutes the cast slough is left hanging in the shrub. The cast sloughs of both the adder and ring snake are held in considerable veneration in the rustic mind, and are credited with various powers of healing. The particular power ascribed to them varies in different localities. Thus the sloughs are believed to have the power of drawing out thorns from the flesh if worn over the point of puncture; of curing rheumatism if worn as a garter round the knee; of preventing sunstroke and curing headache if put on round the head. The young of the adder cast their first slough in the embryo, which can be seen in an illustration in the chapter on the development of that species. 75 CHAPTER VII. VIPERA BERUS, OR ADDER. DISTRIBUTION-DESCRIPTION-AVERAGE SIZE-MARKINGS AND COLOURS-HAUNTS-FOOD. We now come to the consideration of our sole venomous serpent in these islands--Vipera berus, the adder, or, as it is often called, the viper. It has been explained in chap. i. of this book why this species will be discussed somewhat more fully than was the case in the two serpents already considered. Distribution.-Vipera berus is distributed over almost the whole of the European continent, the extreme north excepted, where the cold is too intense for serpents to flourish. In Scotland it is much more common than the ring snake, while in England its distribution is very various, and will be found under the head of the separate counties, in a later chapter. In Wales it is very common in some places, rare in others. Like the other ophidians, it is absent from Ireland. It is frequently seen in the islands of Mull and Jura. Description. 1. Size.-Some confusion has arisen in the minds of some as to the size of the adder, from the fact of the small red viper not being regarded as a distinct species, a most excellent work on Natural History thus making the statement that the "average size of the common viper is 10 inches." The fact of the matter is that the small red viper averages this figure, but the common adder has a very different measurement. A reference to the figures in the various counties will show that the average size of the adult adder in this country varies from 18 inches to 25 inches, according to the locality. When I was working up the Ophidia of the Monnow Valley I was very much. struck with the large size of the adders there, and wrote to G. A. Boulenger on the subject. I had then recently obtained a specimen measuring 281 inches, and was anxious to know what this authority thought of it. His opinion on this matter is probably of more value than any other that could be obtained, as many of the interesting specimens taken in this country go to him at the British Museum. Mr Boulenger says: "The usual size of adult vipers in this country is from 20 to 25 inches, specimens of 26 inches being very rare. I have no British example measuring as much as 28 inches. The largest specimens in the British Museum measure 680 millimetres (tail 70), female, from Crowborough, Sussex. Our largest Continental adder measures 700 millimetres. It is, therefore, inch short of 28 inches." a It This is a very important point, as the general idea of the size of the adder is that it is seldom more than 18 inches long. I remember a gentleman once solemnly assuring me that any snake in this country which measured over 18 inches was perfectly harmless, and must be a ring snake, which seems to be the usual, but erroneous, idea, and, moreover, somewhat dangerous one if put into practice. must always be remembered that not every adder seen is an adult; and it is probably true to say that if an adder be killed measuring less than 18 inches, it is a young one, the parents of which, could they be compared with it, would be found to measure several inches more. Another point in connection with the size is that the female adder in any given locality averages from half an inch to an inch and a half more than the male in length. 2. Markings. The markings of adders are very well defined, and serve at once to distinguish them from the two innocuous serpents. These markings are seen to perfection in a young adult male just after point to which they the slough has been cast. They are the same in general character in the female, but not so brilliant. At the back of the head, which is flattened, there are two narrow dark or black bands, converging to a point on the top of the skull. These two dark bands may or may not join at the converge; as a rule, they do not quite join. They form the well-known characteristic V-shaped mark, the point of the V being towards the snout of the adder. But this V-mark, although always present in adders, shows endless variety. As I write, there are a number of preserved adders on the table before me, and on looking closely at them seriatim, it is noticeable that the mark is slightly different in each specimen-very different, indeed, in some from others. The following drawing (natural size) shows some of these variations. The figures under each drawing refer to the length of the adder to which the marking belongs, measured in inches. These specimens were taken haphazard out of my collection, and they show well that the V-shaped mark is a very varying Immediately behind the V the adder is of a bright yellow colour very often, showing up the dark markings more prominently. Then, proceeding in the description along the back, the zigzag black line is noted, the first patch of which is shown in the drawings. This first patch also varies greatly in shape, but as it goes along the back it becomes more regular. This line of markings is continued one. |