The Ciliuin. 189 



account. We should not expect the fibriUar structure to remain nor- 

 mal in tissue treated with most of them. Fibril! ae in the cell should 

 show the same structure that cilia show after treatment with any 

 one reagent. Thus, osmic acid would leave the fibrillae normal, 

 strong and weak Flemming would break them up into short twisted 

 threads, mercuric bichloride would in some cases leave them almost 

 normal (HgCl sat. in nornuil salt), and in others fuse them so they 

 entirely disappear. Alcohol would break them up in densely granu- 

 lated masses, acetic acid would leave them more granular than 

 alcohoJ, chromo-acetic and })icric acid would leave them fused masses, 

 while formol would show them as threads. 



Structure of Flaget.la as Demonstrated by Teasing. 

 Introduction. 

 There is almost universal agreement in the literature on the Flagel- 

 lum that this organ is "Ein homogener diinner Faden, der keinerlei 

 besondere Anhangsel tragt." This is the view of Kunstler, Loffler, 

 Biitschli, Ivlebs, Hertwig and, more recently. Putter. Tn 1894 

 Fischer came forward with the view that a number of flagella, the 

 Flimmergeissel (Euglena viridis and Monas guttula), "Besteht aus 

 einem homogenen Faden, der mit einer oder mehreren Reihen kurzer, 

 diinner, zugespitzter Hiirchen (Cilien) besetzt ist." On the other 

 hand, another class of Flagella, the '^Peitschengeissel," consists of a 

 homogeneous thread that often shows fibrillae clinging to it. So far 

 as I know, Fischer's results have not been confirmed; and my own 

 observations have yielded nothing approaching his figures or descrip- 

 tions. Putter, because of the structure of the flagellum, rejected the 

 fibrillar theory of the structure of cilia. 1 hope to show that in its 

 structure is really the best justification for his theory. 



MefJtod and Materials. 

 For this investigation the flagella of Euglena, Chilomonas Parame- 

 cium and Spirillum (Sp. ?) were used. Mounts from infusions con- 

 taining the first two of these forms were i)laced under a 1,5 mm. oil 

 immersion and subjected to pressure. 



