Apart from a few fragments, all surviving Anglo-Saxon medical texts belong to the last two centuries of the Anglo-Saxon period. Whatever we can learn about earlier medical practices, we must glean from non-medical sources. The earliest surviving writings of an Englishman are those of Aldhelm of Malmesbury, who wrote in the late seventh and early eighth centuries. In his Enigmata we find a few references to medicine which give a glimpse into the medical practices of his day. In Enigma xliii he wrote of the medicinal leech (sanguisuga): ‘But I bite unfortunate bodies with three-furrowed wounds and so bestow a cure from my healing lips.’ This refers to the use of the medicinal leech to withdraw blood and perhaps to a belief that there is healing in its bite apart from its withdrawal of blood. It is interesting that nowhere in Old English medicinal texts is the bloodletting use of the leech mentioned. About the beaver Aldhelm wrote: ‘Also, a healer, wounds of the entrails and limbs lurid with wasting and contagion and killing plague I disperse.’ Castoreum, which is a medically active product of the inguinal glands of the beaver, was a valued medicament in ancient medicine but, so far as I know, was not prescribed for the ailments mentioned by Aldhelm, nor is it mentioned in surviving Old English remedies.