By his help, with that of Saint Isidor, Saint Epiphanius, and Hugh of Saint Victor, we can decipher the figurative meaning of monsters.
"They are all alike; there has been no complete or serious work produced on symbolism since the Middle Ages, for the Abbe Auber's work on the subject is a delusion.

In vain will you seek for a treatise on flowers which even alludes to the Catholic significance of plants.

I do not, of course, mean those silly books compiled for lovers, and called the Language of Flowers, which you may find on the bookstalls with old cookery-books and dream-books.

It is the same with regard to colours; nothing proven or authentic has been written concerning infernal or celestial hues; for in fact the treatise by Frederic Portal is worthless.

To explain Angelico's work I had to hunt here and there through the Mystics, to discover where I might the meanings they ascribe to colours; and I see plainly that I must do the same for my article on the emblematical fauna.