132 D. H. WENRICH 



sublimate-acetic slides the chromatic basal rod was not so in- 

 tensely stained as in those fixed in Schaudinn's. Similar results 

 were obtained by the use of Allen's and Bouin's fluids, except all 

 structures appeared swollen in comparison with those prepared 

 with other fixatives. Also the free flagella were better stained 

 after the last two fixatives named than after the first two. In 

 the case of Carnoy's fluid (fig. 1) the results varied considerably 

 with the stain. In the animals showing an average intensity 

 of the stain, the nucleus was very black, often failing to show 

 any structure, while the chromatic basal rod and the chromatic 

 margin of the membrane failed to stain. In contrast, the two 

 rows of chromatic granules were stained very deeply. In the 

 specimen drawn (fig. 1) the chromatic margin was not so strongly 

 stained as is indicated and the nucleus was lighter than in the 

 majority of individuals. The blepharoplast was also faintly 

 stained on these slides, while the free flagella and the axostyle 

 were farely well defined in most cases. After weak Flemming's 

 fluid all the structures were rather indistinctly differentiated by 

 the stain, and yet these slides were the only ones in which the 

 parabasal body appeared. 



I did not find the parabasal body until after reading the paper 

 by Cutler ('19), who describes its occurrence in Ditrichomonas 

 termitis. According to Cutler, this structure was not constant 

 in material prepared with the usual fixatives, but by employing 

 Flemming's without acetic acid and other fixatives which con- 

 tained neither acetic acid nor corrosive sublimate, he was able 

 to demonstrate it consistently. Following his suggestion, I 

 employed on the same lot of material from mouse no. 29 Allen's, 

 Bouin's, and Flemming's fluids each without acetic; also 1 per 

 cent chromic acid containing 1 per cent urea and several strengths 

 of formalin, together with unmodified Schaudinn's and Allen's 

 fluids as controls. The latter two fluids gave the best general 

 fixation, but the Flemming's without acetic and the 1 per cent 

 chromic acid both brought out the parabasal in some individuals 

 when subsequently stained with iron-alum haematoxylin. Since 

 Janicki ('11) found the parabasal in T. bactrachorum which 

 had been fixed with an 'osmic acid mixture,' I was led to scrutin- 



