250 



The Unity of the Organism 



Figure 6 shows numerous details of the system of external 

 organs of Stylonychia histrio. The figure was made from a 

 section of the peristomal field. Special attention is called to 

 the finely striated appearance of the membranellae, in I, and the 



M1- 



FIGURE 6. STYLONYCHIA HISTRIO (AFTER MAIER). 



Ml)])., preoral membrane. Se., frontal cirrhi. Bs., basal strand. 

 Us. 1 , basal strand of membranellae. J., endoplasmic inclusions. lif., 

 basal fibers, p., pellicula. F.n., emloplasm. 



pre-oral membrane, m bp, these striae being evidence that the 

 organs are produced by a fusion of cilia. The distinction be- 

 tween the basal lamella, bl, and the basal granules should also 

 be noticed. The investigation from which this figure is taken 

 is particularly instructive because it is based on a large num- 

 ber of representative genera and because the discussion brings 



