250 CILIATE FIBRILLAR SYSTEMS 



ing from the right to the left of the body, (2) the caryophore fibrils, 

 and (3) the shelf-supporting fibrils (Fig. 89). 



Methods 



Fixatives: Schaudinn's (5-percent acetic), Fiemming's. 



Stain: Heidenhain's iron haematoxylin, aqueous and alcoholic. 



Silver techniques: Klein, Gelei-Horvath, Yabroff (negative). 



Spirostonium anibiguum Ehrbg. (Bishop, 1927). — The ridges and 

 furrows in the ectoplasm of Spirostonium ambiguum follow a sinistral 

 spiral course from the anterior to the posterior end of the body. Be- 

 neath the furrows lie thread-like myonevies, somewhat beaded in ap- 

 pearance, but without light and dark alternating bands. The rnyonenies 

 taper gradually as they approach either end of the body and finally disap- 

 pear from view. They are not attached to any structure. Longitudinal 

 rnyonenies were found on either side of and running parallel to the band 

 of peristomal membranelles, except along those membranelles nearest 

 the cytostome. No evidence was obtained confirming the presence of 

 other fibrils such as neurophanes. 



On the anterior side of each niyoneme lie the basal granules of the 

 body cilia. The rows of granules are parallel to and slightly above the 

 level of the rnyonenies. No ciliary rootlets nor connections between basal 

 granules or myonemes were discovered. 



The system of fibrils underlying the membranelles (Fig. 90) of 5. 

 ambiguu?n includes: 



an anterior basal fibril extending from the anterior end of the body to the 

 beginning of the peristomial depression ; a middle fibrillar system which 

 varies in its course in diiferent individuals, but which collects the end-threads 

 of the membranelles lying on the left side of the peristomial depression ; and 

 a posterior basal fibril into which the end-threads of the membranelles at 

 the posterior end of the peristomial depression and in the cytopharynx join. 

 A connection between the posterior basal fibril and the middle fibrillar 

 system is seldom found, and there is always a break between the middle 

 fibrillar system and the anterior basal fibril. 



A central body to which the fibrils join was found in no case. 



Methods 



Fixatives: Schaudinn's, picro-mercuric (hot). 



Stains: Iron-haematoxylin (alcoholic and aqueous), Mallory's triple 

 (Sharp's modification), Fuchsin S. 



