. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. STRUCTURE AND DIVISION OF ANCISTRUMA STRAND 5 Peripheral Cilia The peripheral cilia originate from rather large basal bodies ar- ranged in longitudinal rows. These rows begin at the anterior field slightly back of the anterior extremity on the ventral surface. They pass backward and around the posterior end, returning on the dorsal surface and around the anterior end to the anterior field. The rows on the ventral surface are more numerous and much closer together than those on the dorsal. In sectioned material this relations
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. STRUCTURE AND DIVISION OF ANCISTRUMA STRAND 5 Peripheral Cilia The peripheral cilia originate from rather large basal bodies ar- ranged in longitudinal rows. These rows begin at the anterior field slightly back of the anterior extremity on the ventral surface. They pass backward and around the posterior end, returning on the dorsal surface and around the anterior end to the anterior field. The rows on the ventral surface are more numerous and much closer together than those on the dorsal. In sectioned material this relationship is clearly brought out (Fig. 2). The basal bodies are connected longitudinally by fine coordinating fibers. The cilia are long and wavy with the exception of a single tuft of tactile cilia at the anterior end on the ventral surface. In this region the basal bodies are small and very numerous, and from each originates a single stiff cilium. The tuft of cilia may be seen easily from a lateral. FIG. 2. Ancistnnna mytili. Camera lucida drawing of a cross-section through the mid region looking from the anterior to the posterior end. Champy's: Crystal- violet, x 1000. view (Fig. 1, C). It may also be seen in life when the organism at- taches itself to the coverglass ventral side up. Then each cilium appears as a tiny point against the glass while the other cilia over the body con- tinue to wave. This tuft of cilia is the attaching mechanism and is un- doubtedly used in anchoring the organism to the mantle and gills of the host. It often attaches itself by this tuft to the bottom of the Syracuse dish or to pieces of debris. Pcristouial Cilia Slightly back of the pointed end of the peristomal groove three rows of very long cilia originate. Two rows follow the dorsal edge of the peristome posteriorly and dip down in an arc behind the mouth. The other follows the ventral edge of the peristome and ends just over the point of the ventral flap. The cilia of these three peristomal rows a
Size: 2018px × 1238px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
