THE FUNDAMENTAL ORGANIZATION 81 



water without loss of organization and may re-establish vitality by 

 subsequent hydration (e. g., as in dried rotifers or protozoan cysts). 

 He maintained that normal structures are not disturbed by such 

 desiccation provided the latter process is correctly carried out. 

 Dried forms obtained in this way were treated with a 2 to 3 per 

 cent solution of silver nitrate, which was allowed to act for from 

 eight to ten minutes. The organisms were then submerged in 

 distilled water and exposed to sunlight. Blepharoplasts or basal 

 bodies of the cortex are apparently composed of a substance which 



' ■ 





c >s 



'.-.'.* ..... ■ .\ • ■ 



Fig. 43. — Podophrya fixa. Silver line system at the time of budding. A, budding 

 region of tentacle-bearing parent organism, aggregation and divisions of primary 

 blepharoplasts; B, later stage with final divisions of blepharoplasts; C, bud in which 

 the blepharoplasts have "satellites" which form the cilia. (After Chatton, Lwoff 

 and Tellier, Compt. rend. Soc. d. biol., 1929, courtesy of Masson et Cie.) 



has an affinity for silver (argentophile substances). The silver is 

 reduced in sunlight and the basal bodies, their connectives and 

 associations are revealed in jet black lines and grannies against a 

 yellow background. Klein termed these structures the silver line 

 system and has shown that, specific systems characterize each 

 species of ciliate (Figs. 41 and 42). 



Chatton and Lwoff (1929) have extended the silver nitrate method 

 for fixed material, thus avoiding the somewhat brutal desiccation. 

 Their results in general confirm Klein's. 

 6 



