THE DEVELOPMENTAL MORPHOLOGY OF TWO SPECIES OF MICROASCUS

Abstract

The ontogeny of the perfect stage in Microascus longirostris and M. irigonosporus has been investigated. Sexuality has also been examined in M. longirostris, M. trigonosporus, M. cinereus, and M. doguetii.Results show that all these species are homothallic, and that perithecial formation in M. longirostris and M. trigonosporus follows the general pattern outlined by previous workers. The author has been able to clarify at least three important developmental phases which had either been ignored or insufficiently described by earlier investigators. These are the formation of the perithecial primordium; the development of the sterile hyphae of the centrum; and the structure and nuclear condition of the ascogenous system.