Studies on the Bmudeate Phase in the Plant-ceVt, 5 



which must have been binucleate at an earlier stage immediately 

 suggested that it was an indication of nuclear fusion. This view we 

 were at first inclined to accept, but further work has led to the 

 conclusion that, it is probably untenable. The converse view, that 

 theje lobings might represent early stages in amitotic division, is 

 at once put out of court by the fact that this stage follows the bi- 

 nucleate stage instead of preceding it. Light is thrown upon the 

 subject by a careful examination of the fertile region of the inflor- 

 escence axis gathered on April 27. Here we find a number of 

 instances in which one nucleus in a cell looks more or less normal, 

 while the other stains homogeneously and is apparently degene- 

 rating (PI. I, fig. 11). Such evidence has, naturally, to be used 

 with great caution to avoid confusing the results of poor fixation 

 with actual degeneration stages, especially when considering 

 resting nuclei, wliich are often less well preserved than those in 

 process of division. It seems improbable, however, that we are 

 dealing with an artefact in the present case, since in the same 

 section phragmospheres and well-preserved nuclei, both in the 

 inesting stage and various mitotic phases, may be observed. One 

 apparently degenerating nucleus and one in the prophase of 

 division have been noted in a single cell. However, though 

 dividing nuclei in all stages are well preserved in our material of 

 ■this species, the preservation of the resting nuclei is throughout 

 less satisfactory, and the possibility must be recognized that our 

 " degenerations " are artefact. 



That one of two sister nuclei of identical age and history in the 

 same cell should degenerate while the other remains normal is 

 perhaps a somewhat unexpected result, but, as we have already 

 shown (p. 3), there is no doubt that, at earlier stages, such pairs 

 may show differential behaviour, one entering upon a second 

 division, while the other remains in the resting stage. We are, on 

 the whole, inclined to think that the ultimate uninucleate condition 

 is brought about by the degeneration and resorption of one nucleus, 

 while the later lobing, whether regular or irregular, is merely a 

 symptom of age and perhaps partial degeneracy. The large-sized 

 nuclei of the Liliaceae must naturally be more liable to collapse and 

 become irregular in outline than smaller and more compact nuclei, 

 such as are generally met with among the Dicotyledons. We do 

 not, however, consider that the possibility of an occasional fusion is 

 ■excluded; the close approximation in which the pairs of nuclei 

 sometimes lie seems favourable to such an event. 



In order to find out whether the cytological features observed 

 bore any relation to the rates of elongation of the different regions, 

 two inflorescences were chosen at the end of April and their axes 

 were marked off with Indian ink into zones 1 cm. in length ; the 

 increase in length of these zones was recorded week by week in the 

 period before fixation. A single example will suffice to show the 



