Five rows of clavate cilia that reside just below the anterior ciliary girdle of Didinium nasutum. This micrograph also shows a partial view of the pectinelle rows of the anterior girdle of cilia. The clavate rows have been proposed to be sensory by some as, like some olfactory or vision receptors of vertebrates, they are basal bodies with short axonemal microtubules but lack central microtubules. This micrograph was taken in 1968 by G. Antipa on a Cambridge Mark IIA operating at 20kV. The negative magnification is 5440X. The raw film was scanned with an Epson Perfection V750 Pro. This image is available for quantitative analysis. Further details are available at Wessenberg, H. and Antipa, G. 1968. Studies on Didinium nasutum. I. Structure and ultrastructure. Protistologica 4:427-447.