 In 1914, Zeller published a study of the development of the mushroom, made possible by the prolific fruiting of the fungus in Seattle in the fall of 1912.Development was studied by examining thin sections of tissues in different stages of development, and the differentiation of tissues and structures followed by using histological stains.The growth form of "Xerocomellus zelleri" is called gymnocarpic, meaning that the hymenium appears and develops to maturity in an exposed state, not enclosed by any protective membrane.