OPAIJNID CILIATE INFUSORIANS — METCALF 617 



(5 inoculations) and B. palustris (2 inoculations), and secondary 

 transfers from artificially infected R. clamitans (1) and R. catesbeiana 

 (1), also inoculations of adult R. catesbeiana with adult Opalina from 

 adult R. pipiens (3) and adult R. palustris (3) and from artificially 

 inoculated R. clamitans were tried, and upon examination about 

 once a month gave the following results: R. clamitans, 5 showed no 

 infection; after inoculation from R. pipiens 2 showed good infections 

 after 162 and 174 days; after inoculation from R. palustris 1 showed 

 fair infection after 16 days, a second 82 days after secondary inocula- 

 tion from an artificially infected R. catesbeiana showed fair infection. 

 Experiments upon R. catesbeiana: 4 showed no infection after inocula- 

 tion; 1 gave a good culture 35 days after inoculation from adult 

 R. pipiens, but none after 71 daj^s; 1 gave a fair culture 105 days 

 after inoculation from R. pipiens; 3 inoculated from adult R. palustris 

 and 1 secondarily inoculated from an artificially infected R. clamitans 

 all were negative, none having established infections. 



Ten Kate, in 1926, regarded the sj^stem of fibrils, described in 

 detail, as having only a supporting function [an interpretation made 

 doubly improbable by Taylor's (1920) microdissections of Euplotes 

 and the destruction of coordination in the beat of the cilia by severing 

 portions of the system of fibrils]. The endosarc spherules are [mis- 

 takenly] regarded as macronuclei. 



Gourvitsch, 1926, redescribed under the [mistaken] name 0. elongata 

 n. sp. specimens of Cepedea saharana Metcalf from R. esculenta ridi- 

 bunda from Tashkent, Turkestan [see Metcalf, 1927b]. 



Da Cunha and Penido, 1926, described Zelleriella piscicola from a 

 catfish (?) from the Paraguay River. 



Tyler, 1926, stated that Opalina may live 25 days without change 

 of medium, in modified Putter's fluid used according to Konsuloff, 

 1922. 



IVIetcalf, 1926: In the tadpoles of the hosts the opalinid parasites 

 start their development in the condition of Proioopalinae of the most 

 primitive subgenus and pass through larval stages corresponding to 

 the phylogeny of the family until they reach their definitive character. 

 Zelleriella passes through a Protoopalina stage; Cepedea through suc- 

 cessive Protoopalina stages, including at least subgenera I and VIII 

 of the present paper; Opalinae latae add to this series the broad, flat 

 stage characteristic of the adult; the Opalinue angustae pass through 

 all these stages, then become definitively narrow, thus confirming the 

 course of the phylogeny as I had before outlined it. 



Klein, 1926, described and figured a very primitive "silver line 

 system" in Opalina ranarum. The basal granules of the cilia and the 

 longitudinal striae impregnate with the silver, the former being 

 blacker. 



