When the spore is coloured, the external membrane alone appears to possess colour, the endospore being constantly hyaline.
"Fungi: Their Nature and Uses"
Mordecai Cubitt Cooke
The endospore is thick and composed of several layers, colourless, and covered with warts, which correspond and fit into those of the epispore.
"Fungi: Their Nature and Uses"
Mordecai Cubitt Cooke