7 8 GENERAL BIOLOGY 



6) Observe the action of the fringe of strong cilia (peri- 

 stome) surrounding the rim of the trumpet, and try 

 to see objects free in the water driven by these cilia 

 into the mouth. If not well seen this may be demon- 

 strated, as for Paramoecium, by adding a little 

 finely pulverized carmine to the water. 



3. Using an eyepiece of higher magnification, study 

 the extended stentor, observing : 



a) The lorica, if present; note its shape, appearance, 

 and consistency. 



b) The disc like attachment of the foot. 



c) The long tapering body, covered with minute cilia. 



d) The flaring distal end, with its encircling peristome, 

 involute at one end to surround the mouth. Com- 

 pare with the peristome and mouth of Paramoecium. 



4. Within the body observe in a specimen having the 

 mouth uppermost: 



a) The short esophagus ending blindly in the endosarc. 



b) Food -balls moved about in the endosarc. 



c) An elongate, moniliform meganucleus, and a micro- 

 nucleus close beside it. The latter is usually hard to 

 see in the living specimen, but may be demonstrated 

 with iodine as in Paramoecium. 



d) A large contractile vacuole, of varying proportions. 



e) Fine nearly parallel lines extending from foot to 

 disc in the ectosarc (myonemes) . 



5. Observe the ordinary reproduction of the animal by 

 division of the single cell into two ; note the plane of the divi- 

 sion, and the relation it bears to foot, disc, peristome and 

 meganucleus. 



The Record of the study of the stentor may well consist in : 



1. A sketch in simple outlines of a little group of 

 stentors in various positions. 



2. The details of structure of a single animal. 



