io BOTANICAL GAZETTE [july 



due to the denser aggregation of the spirem in these regions, but 

 in some cases it is evidently due to the presence of bodies which retain 

 the stain and appear to be giving up the stainable part of their sub- 

 stance to the spirem. These bodies are evidently not the prochromo- 

 somes found by Overton (22) in certain dicotyledons, nor are they 

 the gamosomes of Strasburger (30, 31). 



Just the relation these bodies sustain to the spirem is not easy to 

 determine. From figs. 12 and 14 it is evident that they are at first 

 small "nucleoli" caught in the contracting reticulum, but quite 

 independent of it. Later they appear to give up a portion at least of 

 their material to the spirem, finally disappearing as independent 

 bodies. Usually, however, at least one of these bodies remains inde- 

 pendent, and appears in synapsis and diakinesis as a small nucleolus 

 bearing a definite relation to the size of the large nucleolus, being 

 about the size of a chromosome. These bodies are usually free in 

 the nuclear cavity (fig. 15). A certain depth of stain is required for 

 demonstrating them during synapsis, for they usually decolorize more 

 quickly than the large nucleolus. With a favorable stain they are 

 found to be of strikingly uniform occurrence at this time. A plasma 

 stain such as orange G may be used with advantage to demonstrate 

 their presence. The uniformity in their occurrence is so great that 

 for some time they were thought to be constant in size and number. 

 With the demonstration of their inconstancy and their origin we have 

 chosen to call them merely small nucleoli, as there appears to be no 

 sufficient reason for another name. The (large) nucleolus disappears 

 with great promptness immediately after the nuclear membrane breaks 

 down, only persisting for a time in a few rare instances. In no case 

 has fragmentation of the nucleolus, previous to its disappearance, been 

 observed, although the presence of deeply staining globular bodies 

 occasionally found near the periphery of the cytoplasm might be 

 accounted for in this way. The mass of the latter, however, is some- 

 times greater than that of the nucleoli. The smaller nucleoli persist 

 and are frequently found close by the heterotypic spindle. They 

 may also be found on the homotypic spindle (fig. 41). Apparently 

 they never reenter a nucleus, but remain in the cytoplasm until they 

 finally disappear. These bodies have been found showing the same 

 behavior in all the forms studied. 



