The main device (symbol) in the Apulstone blazon is the goat. The two main tinctures (colors) are sable and argent.
Sable, the deep black so often found in Heraldry is believed to named from an animal of the marten family know in the middle ages as a Sabellinœ and noted for its very black fur 1A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1894, Entry:Sable. In engravings, when colors cannot be shown it is represented as closely spaced horizontal and vertical lines, and appropriately is thus the darkest form of hatching, as this method is known 2Boutell’s Heraldry, J.P. Brooke-Little, Warne, (revised Edition) London 1970, P 26. Although it may seem a sombre tone, and does indeed sometimes denote grief, it is more commonly said to represent Constancy 3The Symbolisms of Heraldry, W. Cecil Wade, George Redway, London, 1898 P35.
Argent is the heraldic metal Silver and is usually shown as very pure white. It is also known more poetically as pearl, moon (or luna) 4Understanding Signs & Symbols – Heraldry, S. Oliver & G. Croton, Quantum, London, 2013, P53. In a sketch or drawing it is represented by plain, unmarked paper 5A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1847, P11.
In the mediaeval period there was no real percieved difference between real and mythical animals, after all, much of the world remained unknown and who was to say what strange and magical creatures existed in distant lands? Nevertheless, real animals 6A Complete Guide to Heraldry, A.C. Fox-Davies, Bonanza (re-print of 1909 Edition), New York, 1978, P191 are perhaps one of the most common sights on coats of arms, especially animals of European origin. The goat Is a typical example of these. Guillim, writing in the 17th century suggested that it may represent a “martial man who wins victory by…policy [rather] than valour”, a diplomat by any other name. 7A Display of Heraldry, J. Guillim, Blome, London, 1679, P119