H..M. WOODCOCK 



13 



M. 



borated by noting the efforts of friends, experienced microscopists, to 

 detect it when I hâve pointed it ont to them. 



Text-figs. 1-3 are from fixed and stained préparations. Figs. 1-2 

 Avere fixed by a spécial modification of Schaudinn's fluid, which I hâve 

 used for several years and hâve found excellent for Protozoa generally. 

 Tliis modification was first described by me in 1916^, and may be 

 known as Woodcock's S. A. A. mixture. It consists of 2 parts of satu- 

 rated aqueous solution of corrosive sublimate and one part of absolute 

 alcohol (or rectified spirit), to which is added 5 p. 100 of glacial acetic 

 acid. The stain used 

 -was Heidenhain's iron- ^ '' 



haematoxylin (the 

 long method). Try as 

 one will, it is often 

 most difiîcult to obtain 

 préparations of thèse 

 small, coprozoic Fla- 

 gellâtes, in which the 

 délicate flagella arc:> 

 well - stained. Some - 

 times, I hâve used an 

 alcoholic solution of 

 Eosin or Fuchsin, as 

 a counter-stain. I hâve 



ound this method to give,the best results, but even so, success is notf 

 invariably attained. If, however, my figures of Spiromonas (pi. 28, 

 Pliil. Trans., 1. c.) be compared with those of Alphamonas, recently 

 described by Alexeieff, which I propose to consider in the following 

 note, it will be seen that mine show the two flagella clearly, whereas in 

 no case does Alexeieff figure both — sometimes, indeed, not even one. 



Text-fig. 1 represents Helkesirnastix major ; fig. 2, H. faecicola ; 

 and fig. 3, the same form stained by Giemsa (after osmic vapour). 

 The accessory flagelliim cannot be detected in a large number of the 

 individuals on the same films from wliicli thèse figures were drawn. 

 While it is probably présent in some, nevertheless, I do not tliink that 

 it is présent in all,because of the fact that in fresh observation-préparations, 



-rO 



- / 



3 



-S 



- io 



-itS 



Fia. 1. Helkesimastix major. — PlG. 2. H. faecicola. — Fio. 3. H. faeci- 

 cola stained by Giemsa (after osmic vapour). x 2250. 



1. Phil. Traiis. Roy. Soc, vol. 207 B, p. 379. 



