Endogenous Bud Formation in the Hypotrichida

Abstract

As a general rule, ciliated protozoans reproduce asexually by transverse binary fission. Suctoria, however, characteristically produce unequal endogenous buds which develop into migratory ciliated larval forms. Endogenous budding has not been reported in the remaining subclasses of the Ciliatea. Observations made by Kent suggest that one member of the Hypotrichida has a larval stage in its life-cycle¹. He observed the development of an embryonic hypotrich, which closely resembled Glaucoma margaritaceum Ehr., into Aspidisca costata Ehr. In the same treatise Kent considers the holotrich genera Glaucoma and Microthorax to be embryonic or transitional phases in the life-cycles of higher hypotrichous forms. No other reference to such life-cycles in the Hypotrichida have been found.