326 WOOLFORD B. BAKER. 



rods. This structure is separate and distinct from the gullet- 

 reservoir system as described in Euglena. They conclude that 

 the reservoir functions primarily in the reception of the discharge 

 of contractile vacuoles which are located on its periphery. Our 

 own observations indicate that all these functions may be exer- 

 cised by the system in Euglena. 



The Nucleus. 



The nucleus of Euglena agilis lies at the center of mass of the 

 body, being located in the region of the center of the posterior 

 flask shaped enlargement. It is spherical to oblong or ovoid in 

 shape. Its chief characteristic is the presence of a large, deeply 

 staining, central body or endosome, the "Binnenkorper' of 

 Doflein and Tschenzoff. Immediately surrounding the endosome 

 is a light hyaline area apparently devoid of chromatin material. 

 The presence of this hyaline layer enables one to observe more 

 readily the budding off of the motor complex, as described below, 

 from the endosome during the early stages of mitosis. 



In the resting nucleus, chromatin granules arranged apparently 

 at the nodes of a linin network, surround the hyaline area. 

 During the early prophase of division distinct chromosomes are 

 formed by the growth and aggregation of these chromatin masses. 

 When preparations stained in iron-alum hajmatoxylin and counter 

 stained with eosin, are destained considerably, the endosome 

 retains the hsematoxylin so as to appear quite dark while the 

 chromosomes appear red with the eosin. This seems to indicate 

 that there is a great deal of linin in the network on which the 

 chromatin masses are lodged. In most instances the masses seem 

 to occur in pairs giving the appearance of dumb-bells. Wenrich 

 describes somewhat the same appearance of the chromatin in 

 Trichomonas. He says that in the anaphase each chromosome 

 becomes constricted and passes into the resting nucleus as a 

 paired structure. 



A nuclear membrane can be distinguished with difficulty with 

 the stains used, yet the shape of the nucleus and its apparent 

 separation from the cytoplasm certainly indicates its presence as 

 well as its persistence during mitosis. 



The endosome appears homogeneous, although vacuoles or 



