COMMENTARY. Nicander says that the amphisbæna is a small serpent with two heads, and small eyes. The scytala, he says, is like the amphisbæna, but thicker and larger towards the tail. Avicenna doubts whether the amphisbæna moves both ways. He says it is a serpent of equal thickness at both extremities, which probably gave rise to the supposition that it had two heads. He calls it a snake of the fragile nature, which description evidently points to the blind-worm. (See further, Matthiolus, Comment. in Dioscor.) We suppose the altahban and alhuidia of Alsaharavius are the amphisbæna and scytala. (Pract. xxx, 2, 19.) He recommends general treatment, namely, the ligature, cupping, scarifications, with cold water to drink. Sprengel inclines to think that the scytala was the _anguis eryx_. He makes the amphisbæna to be the _anguis fragilis_, L.; he questions, however, the accuracy of the ancient accounts respecting its venomous qualities. (Notæ in Dioscor.) But, indeed, Aëtius states distinctly that these serpents are not venomous, and that their sting merely occasions inflammation like that of wasps and bees. (l. c.) Nicander also merely describes these serpents, and says nothing about their being venomous. SECT. XIV.—ON THE DRYINUS. THE INTRODUCTION FROM GALEN. The dryinus, that lives at the roots of oaks, is so pernicious and destructive an animal, that if one tread on him he will excoriate one’s foot, and great swelling will seize upon the whole limbs; and, what is more wonderful, they say that if one attempt to dress the wound, one’s hands will be excoriated; and that if any person attempts in defence to kill the animal, he emits such a stench as overpowers all other smells. When one has been stung by the dryinus, tumefaction of the part takes place with redness, and blisters on the surrounding parts, along with a discharge of a watery ichor. These symptoms are followed by cardialgia and tormina. Birthwort given as a draught with wine is serviceable in these cases, and the herb trefoil, and the root of asphodel, taken in like manner, and the fruit of all kinds of oak triturated and taken in a draught. In like manner the roots of the ilex pounded and applied to the part are of use. * * * * * COMMENTARY. Nicander says it is also called chelydros and hydros. He makes a distinction between the chelydros and the chersydros, but subsequent authorities confound them together. (See below.) He says it inhabits lakes and marshy grounds, feeding upon locusts and frogs. Its back is black, and its smell fetid. The symptoms occasioned by its sting are livid swelling, delirium, cutaneous pustules, dimness of vision, suppression of urine, coma, singultus, and vomiting of blood or bile.