292 ELERY R. BECKER. 



The chromosomes arrange themselves in an equatorial plate, 

 and a spindle forms. Fig. n is an exact drawing of the spindle 

 at the time it first comes into evidence. The poles of the spindle 

 are the blobs of chromatin at the poles of the nucleus in which the 

 intradesmose had previously terminated. There is some evidence 

 that these blobs of chromatin are not the centrioles, but that the 

 centriole lies within them; e.g., Fig. 2 shows what appear to be 

 two centrioles lying against the chromatin blobs. 



As mitosis progresses the spindle elongates considerably, the 

 nucleus elongating simultaneously and the nuclear membrane 

 commencing to dissolve. The polar blobs of chromatin disap- 

 pear, leaving the tiny centrioles at the poles of the spindle (Fig. 

 3). The chromosomes of the dividing equatorial plate of the 

 early anaphase become massed together so that it is not possible 

 to count them, although in some cases they may appear as a mass 

 of discrete granules. 



The oral apparatus of the parent cell (right and left supporting 

 fibrils, blepharoplasts, etc.) has degenerated. The centrioles 

 divide, leaving connecting rhizoplasts between each centriole and 

 its daughter blepharoplast. The daughter blepharoplast divides 

 at least once (perhaps more), and from the products of the 

 division the left and right supporting fibrils of the mouth grow 

 out. The intradesmose is in evidence along the nuclear mem- 

 brane, connecting the centrosomes at the poles of the spindle. 



The intrazonal spindle fibers disappear in the late anaphase, 

 and the two halves of the equatorial plate are disconnected from 

 one another (Fig. 4). The remains of the spindle attaches the 

 chromatin mass to the centrioles, while a fine rhizoplast connects 

 the centriole with the blepharoplast complex. Fig. 4 appears 

 inconsistent with Fig. 3 in regard to the points of attachment of 

 the intradesmose which traverses the cell. It is extremely 

 difficult to resolve the granules exactly, and the writer has put the 

 intradesmose in each case exactly where it appeared to be. At 

 this stage the "parabasal body" has appeared, and lies in its 

 permanent position, just dorsal to the right supporting fiber. 



The cell constricts in the middle (Fig. 5). The two daughter 

 cells then reconstruct themselves, each with a complete new set 

 of cell organelles. During division no food particles can be seen 

 in the cell protoplasm. 



