194 LORANDE LOSS WOODRUFF AND HOPE SPENCER 



seizing organ, Calkins^^ apparently showed that there is such an 

 effect, and in the absence of trichocysts interpreted certain deeply 

 staining 'granular striae' near the apex of the trichites comprising 

 the seizing organ as representing the seat of the poison. Ac- 

 tinobolus radians also may be mentioned; both Erlanger and 

 Calkins^- held that this ciliate captures Halteria grandinella by 

 means of trichocyst-tipped tentacles. But Moody's study of 

 Actinobolus reduced the 'trichocysts' to 'dark granular trichocyst 

 material.' ^^ 



There is nothing comparable in structure nor, so far as has 

 been proved, in function between trichocysts, in the original 

 sense of the term, and the 'ofTensive trichocysts' described by 

 Maupas, the 'needleform trichocysts' of other authors, or 'tricho- 

 cyst material' of still others. Although in the present state of 

 knowledge the line of demarcation is ill defined in many cases 

 between bodies which are purely supporting in function, others 

 which possibly are both supporting and offensive or defensive, 

 and lastly true trichocysts, only confusion is served by extending 

 the significance of the word trichocyst, which in sensu strictu has 

 a very definite connotation, to widely divergent structures. ^^ 



Trichites. Although trichocysts are not present in Spathidium, 

 there are slender rodlets imbedded like a paling in the thickened 

 rim of the anterior end of the cell which give it a striated appear- 

 ance under certain conditions. These apparently are what 

 Moody (fig. 18) interprets as parallel thickenings of the cortex 

 which reinforce the pharynx. As a matter of fact, the rodlets 

 may be identified as trichites, provided the use of this term does 

 not necessarily imply that they are the seat of the poison. In 

 addition to the trichites in the oral region, it is possible to identify 

 individual trichites distributed intheendoplasmof thecell. Some 



1^ G. N. Calkins, Didinium nasutum: I. The life history, Jour. Exp. Zool., 

 1915, vol.19, p. 225. 



IS G. N. Calkins, The Protozoa, 1901, p. 50. 



i^Loc.cit., p.372. 



2" E. Maupas, Contribution a I'Etude Alorphologique et Anatomique dcs 

 Infusoires Cilies. Arch. d. Zool. Exper. et Gen., 1SS3, (2), 1, p. 611. Y. Delage 

 and E. Hcrouard, La Cellule et les Protozoaires, Paris, 1896, p. 434. 



