From another page on your source, Bill, discussing the history of the manuscript:

The first family consists of the Physiologus plus extracts from the Etymologies of Isidore of Seville. Isidore, living in Spain in the seventh century, explained the true nature of animals by analysing their names. So, a cat is called catus because he catches mice. Isidore's encyclopedic work was not moralised.

The Etymologies of Isidore of Seville can be found at: http://makeashorterlink.com/?C22D11906

Bingley

Bingley