STUDIES ON CILIATED CELLS . 243 



of rootlets of the cilia, as are described by Eberth ('66), Gaule 

 ('81), Lenhossek ('98), Benda ('99), Kolac6v ('10) and others 

 are produced by a linear arrangement of mitochondria; on the 

 other hand, however, there is no reason for believing the exist- 

 ence of such straight rootlets free from nodes, as are figured by 

 Apathy ('97), Heidenhain ('99), and Erhard ('10). 



IV. FUNCTION OF THE CILIARY APPARATUS 



Although this complex and difficult problem has received 

 much attention, it is still far from a satisfactory solution. The 

 review of the literature concerning this is given by Putter ('03), 

 Erhard ('10) and Prenant ('14) to which the reader is referred 

 for details. It may be briefly summarized as follows: 



1) Some authors (Putter, '03; Gurwitsch, '04; Erhard, '10; 

 Kolacev, '10) admit an active mobility of the cilia, others (Peter 

 '99) a passive. 



2) As to the function of the basal corpuscles, some look upon 

 them as a. kinetic center of the ciliary movement (Henneguy, 

 '98; Lenhossek, '98; Peter, '99; Joseph, '03), others as an end- 

 organ of the nerve (Apathy, '97), and still others as a support- 

 ing organ (Eismond, '00); Maier, '03; Kuperwieser, '06; Erhard, 

 '10; Kolacev, '10). 



3) The rootlets of the cilia are regarded (a) as exhibiting 

 contractibility and mobility (Stuart, '67; Simroth, '76; Benda, 

 '99); (6) as primitive fibrillae of the nerve (Eimer, '77; Apathy, 

 '97; Metalnikoff, '00); (c) as a nutritive organ (Engelmann, '80; 

 Kolacev, '10); (d) as a supporting organ (Peter, '99; Eismond, 

 '00; Maier, '03). 



It is necessary to say here a few- words as to whether proto- 

 plasm or nucleus takes part directly in the ciliary movement. 

 Of course, all protoplasm may be endowed with contractility, 

 but there is no reason for supposing that it causes directly the 

 ciliary movement, except that it may furnish a fresh supply to 

 the ciliary apparatus; otherwise such special cell-organs, as the 

 basal corpuscles and the rootlets of the cilia, would lose their 

 significance. This is sufficiently demonstrated in the experi- 

 ments of Peter ('99) which show that ev'en where the ciliated 



