THE DISCOMYCETES OF EASTERN IOWA. 233 



The asexual method of reproduction consists in the formation 

 of spores which are called gonidia or conidio-spores. When 

 present they may often be seen in the form of delicate chains, 

 each of which is composed of a great number of minute globu- 

 lar, or slightly elongated bodies which are formed by a series 

 of constrictions in a simple or branching aerial hypha. These 

 minute reproductive bodies are broken apart at maturity and 

 carried away by the wind or other agency to produce a new 

 fungus. In addition to the ordinary method of asexual re- 

 production these plants may also be reproduced vegetatively. 

 Portions of the mycelium may be kept in a dry condition for 

 an indefinite length of time and finally made to revive and 

 grow by placing them in a moist chamber with suitable 

 material for nourishment. 



The sexual method of reproduction is much more difficult 

 to study, especially in its early stages, but in general takes 

 place in the following manner as described by DeBary for 

 Ascobolus furfitraccus Pers. PI. XV Fig. 11. The method 

 varies somewhat with different species. 



A branch arises from the mycelium and becomes very much 

 enlarged at its upper extremity and separated by transverse 

 walls into a number of cells which are well provided with 

 protoplasm. This hyphal branch is called the archicarp. 

 Other branches arise from near its base which grow upward 

 and apply themselves at its extremity. This contact is fol- 

 lowed by the production of another mass of hyphae which en- 

 tirely surround the archicarp and become closely united form- 

 ing a layer of tissue which is called pseudo-parenchyma. The 

 outer layer of this tissue forms a rind, some of the cells of 

 which send out rhizoid or root-like hyphse into the sub- 

 stratum below and in many species, still other cells produce 

 hairs, differing in form and structure, which cover the exterior 

 of the cup. Sterile branches called paraphyses are given off 

 at the apical region just beneath the rind, or perithecium. 

 This constitutes the beginning of the hymenium or fruiting 

 surface. As new branches are thrust up between the old ones, 



