In the Adinidae there is no groove; the two lashes arise close together, and the one is coiled round the base of the other.
In Unt. Inst. Tübingen, i. 1883, p. 233.
Conjugation of adults has been observed by Zederbauer (Ber. Deutsch. Ges. xxii. 1904). A short connecting tube is formed by the meeting of outgrowths from either mate; their protoplasmic contents meet and fuse herein to form a spherical resting-spore, as in the Conjugate Algae.
According to Bergh, Polykrikos has as many nuclei as grooves, each accompanied by one or more "micronuclei." Possibly these latter bodies are merely blepharoplasts, in connexion with the transverse flagella.
Engler and Prantl's Pflanzenfamilien, 1. Teil, Abt. 1, 1896.