The Morphology of Blepharisma undulans Stein*†

SYNOPSIS. Electron‐microscope studies have revealed the ciliature and infraciliature of Blepharisma undulans to include tubular filaments about 24 mμ in diameter. As these filaments pass from the kinetosomes into the surrounding cytoplasm they appear to divide into double helical subfilaments, each with a diameter of about 12 mμ. In the somatic region the ciliary rows are composed of series of paired kinetosomes. Connected with the anterior member of a pair are the cilium and transverse filaments, the posterior member giving rise to the posterior kinetodesmal fiber. From between the two kinetosomes arises the anterior kinetodesmal fiber. The kinetodesmal fiber system is associated with the subpellicular fibril system which lines the area just beneath the pellicle of the animal. In the oral region a series of these filaments extends from the proximal portion of the adoral zone of membranelle kinetosomes into the cytoplasm. They traverse the oral area to connect with the undulating membrane on the right margin of the mouth. Also present are fibers comparable to the kinetodesmal fibers and transverse fibers of the somatic region. The functional significance of this system is discussed. The nucleus and nuclear and cytoplasmic inclusions are described, including pigment granules, storage products, the Golgi apparatus, mitochondria and vacuole systems.