PROTOPLASM OF PROTOZOA 75 



at 55° C. On the other hand, in Leptomonas ctenocephali the attached 

 forms are held in position by the sHmy enlarged tip of the flagellum, 

 which is much shortened; they are killed at 55° C. before they can re- 

 lease their hold. 



Adhesion phenomena have recently been introduced for diagnosing 

 trypanosomiasis. In adhesion tests a drop of Trypanosoma suspension 

 is added to one drop of equal parts of blood and 2-percent sodium cit- 

 rate. If the blood comes from an infected animal, the red blood cells, 

 and occasionally blood plates as well as bacteria, adhere to the trypano- 

 somes. The immune serum contains an antibody that apparently acts 

 upon the surface of trypanosomes to make it sticky. This test has been 

 recently used by Taliaferro and Taliaferro (1934) in connection with 

 other tests in equine trypanosomiasis; the adhesion phenomenon may 

 persist for more than two years in animals that have been infected, 



Faure-Fremiet (1910) has emphasized the fact that while motility 

 is the more general, it is not the only property of cilia. They may be- 

 come immobile and serve as rigid stalks, or may be reduced to short rods 

 and serve for fixation or for protection to the cell that bears them. It has 

 frequently been observed that the movements of ciliates often cease tem- 

 porarily when they come in contact with a firm surface. According to 

 Jennings (1906) "the cilia that come in contact with the solid cease 

 moving, and become stiff and set, seeming to hold the Paramecium 

 against the object." Saunders (1925), however, holds that partially 

 extruded trichocysts with sticky tips serve as temporary attachments in 

 Paramecium. The hypotrichs generally can creep along vertical surfaces 

 and on the under surfaces of the cover glass. The hypotrich Ancystro- 

 podium maupasi may attach itself by its posterior cirri (Faure-Fremiet, 

 1908) , and the holotrich Hemispeira by a bundle of fixative cilia (Faure- 

 Fremiet, 1905). Kahl (1935) thinks that such adhesion depends upon 

 the ability of cilia to become sticky, at least at the tips. Cilia are associated 

 with attaching organs in Trichodina and in Ellobiophrya (Chatton and 

 Lwoff, 1923a). Chatton and Lwoff (1923b) have also described organs 

 of attachment derived from the posterior ciliated region in the Thigmo- 

 tricha, Faure-Fremiet (1932) has studied the fixatory apparatus of 

 Strombidium calkinsi which is constituted by two dorsal membranelles 

 nearly as long as the body and made up of coalesced cilia which separate 

 from each other at the adhesive distal extremity. At times the ciliate 



