This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Johnson, D. L. Articles by Gamow, R. I. Search for Related Content PubMed PubMed Citation Articles by Johnson, D. L. Articles by Gamow, R. I. Agricola Articles by Johnson, D. L. Articles by Gamow, R. I.

Articles

Phycomyces: Growth Responses of the Sporangium

^a Department of Aerospace Engineering Sciences, University of Colorado, Boulder, Colorado 80302

During the development of the sporangiophore of the fungus Phycomyces blakesleeanus there occurs a period of several hours when the sporangiophore does not elongate; instead, its "growth" is diverted into the formation of a sporangium at its top. This period of head formation is called stage II. Clearly, growth has not ceased but rather the geometry of the growing area has changed from that of a cylinder to a sphere. The growing sphere is found to have properties similar to the stage IV growing zone in that it functions as a sensory receptor and effector. The growing sporangium responds to both light (light head response) and humidity (wet head response). A model is presented giving a possible mechanism by which the ultimate size of the sporangium is regulated.