310 KOFOID AND SWEZY. 



A close inspection of our figures shows, however, especially in the case 

 of mitotic stages (PI. 2, Figs. 11-23) and some others (PI. 1, Fig. 2) 

 that we must view the axostyle on other faces than those above noted, 

 but only lateral positions of these so-called fibrillae are to be seen in 

 these cases also. Furthermore, in the macerated extra-nuclear motor 

 apparatus (Fig. D, 4) no trace of Kuczynski's fibrillae can be found, 

 nor of the location of the blepharoplast between their anterior ends 

 as he intimates. The axostyle is rather a subcylindrical rod with 

 enlarged anterior end with no trace of fibrillar structure but with a 

 sheath or outer layer of greater stainability, especially posteriorly, 

 than the hyaline interior. 



The function of the axostyle has been interpreted by Grassi (1888) 

 as a "squelette interne," by Kunstler (1898) as skeletal since its 

 "courbe reguliere et tendue denote une certaine rigidite jointe a une 

 grande elasticite," and this view has been generally accepted by those 

 who have since discussed it. Dobell (1909), for example, insists 

 "that its real function is entirely skeletal" and that "it is merely an 

 axial support." Kuczynski (1914) seems also to accept this view 

 citing in support the view of Hartmann and Chagas (1910) that the 

 slender axostyle in Cercomonas parva is a firm elastic structure not 

 subject to contraction, that is to decrease in length with the amoeboid 

 changes in form of the body which alone are responsible for its changes 

 in shape. He notes, however, that the skeletal function is possible 

 only while the two ends of the axostyle are fast to the outer membrane, 

 and that the posterior attachment is often released with the result 

 that the axostyle is entirely included within the cytoplasm. He 

 concludes that it then ceases to be a " formgebendes Element" and is 

 speedily resorbed as a result of inactivity. No previous activity is, 

 however, attributed by him to the organ. 



Kunstler (1898) has also suggested that the projecting point is an 

 organ of fixation. Wenyon (1907) accepts this view and Kuczynski 

 (1914) narrates an observation which leads him to champion it. He 

 observed that the tip of the axostyle is thrust into the substrate by the 

 activity of cytoplasm and that when thus anchored the flagella be- 

 come quiet while the undulating membrane proceeds to fill the cyto- 

 stome with food particles by its activity. 



In our observations such attachments are not infrequent, l)ut they 

 seem rather to be due to the adhesive nature either of the substrate 

 or of the organisms which under cover glass speedily become adhesive. 

 That the protruding axostyle is especially adhesive is often seen in 

 the string of bacteria or detritus trailing after its tip in free-swimming 



