356 JULIA ELEANOR MOODY 



the cuticle (figs. 3 and 12). Biitschli mentions sixteen or more 

 club-shaped, contractile rods, which Maupas interprets as tri- 

 chocysts. Without doubt the trichocyst material is located in 

 this region, since Colpidium, paralyzed when touched by the 

 anterior end, suffers no evil consequences by contact with any 

 other part of the body. Three artificial methods were used to 

 explode the trichocysts: exposure to osmic acid vapor, treatment 

 with a 2 per cent solution of acetic acid and a solution of methyl 

 green. After treatment with any one of these reagents, in fifty 

 individuals examined, the cilia were found fully extended, the 

 trichocysts being readily distinguished from the long oral ciha 

 inasmuch as they were stiff and straight in appearance, whereas 

 the ciha showed a wavy outline. Mitrophanow in his contri- 

 bution, "Etude sur la structure, le developpement et I'explosion 

 des trichocysts des Paramoecies" describes the presence of small 

 bodies in the region of the nucleus which take the nuclear stain. 

 Among these deeply staining masses he found a variety of forms, 

 ranging from spherical granules to rod-shaped bodies, similar 

 in structure to the typical trichocyst, and although he did not 

 actually observe the extrusion of these particles from the nucleus, 

 he thought it probable that the trichocyst material is of nuclear 

 origin, migrating from the interior of the cell toward the per- 

 iphery. Here by proper stinmlation the cortex contracts, the 

 semi-fluid trichocyst material is forced out, solidifying as it 

 comes in contact with the water. I have seen in Spathidium 

 no deeply staining particles, originating in the region of the 

 nucleus, which could be interpreted as developing trichocysts; 

 neither have I found the greatly elongated trichocysts of com- 

 plicated form described by Meier, Schuberg and Schewiakoff 

 for Frontonia, Paramoecium and some other ciliates; owing, 

 however, to the paralyzing effect on Colpidium following con- 

 tact with the anterior end of the body, I think it safe to interpret, 

 as trichocysts, the short opaque rods so plainly visible in the 

 thickened rim of the mouth. 



The mouth opens into a space, the pharynx, reinforced bypar- 

 allel thickenings of the cortex as shown in figure 18. Imbedded 

 in the protoplasm are numerous food vacuoles, the contents 



