3o8 LESTER W. SHARP 



at a stage earlier than that figured by Fraser and Snell, arnong the rather 

 loosely packed chromosomes. It is difficult to say what its relation to the 

 latter may be. Since it is stained intensely even after ail color has been 

 removed from the chromosomes it is évident that the relation is not prim- 

 arily a morphological one. That there is an indirect ph3^siological connection 

 between the activity of the chromosomes and the appearance of the nucleo- 

 lus can hardly be doubted. 



A later stage of the telophase is shown in fig. 39 (the figure is accom- 

 panied by a small schéma to facilitate explanation). The nucleus has in- 

 creased considerably in size, as has the nucleolus. The chromosomes with 

 their Connecting anastomoses form a continuons reticulum fiUing the whole 

 cavity, but the limits of each are easily discernable (compare schéma). 

 A comparison of fig. 38 and 39 will aid in interpreting the latter. The 

 chromosome a of fig. 39 was vacuolized mainly along the central partion, 

 as in the longer chromosome of fig. 38c. On the other hand, the vacuoles 

 of the chromosome d were produced almost entirely along one margin, as 

 in the lower portion of fig. 38^. With thèse two examples occurring in the 

 same nucleus with others showing a much greater irregularity it is plain 

 that \ve cannot speak of longitudinally split chromosomes at this stage. 

 The true relation of this irregular vacuolization to the splitting of the chro- 

 mosomes can be discussed only after the phenomena of the prophase hâve 

 been considered. 



Interphase. 



For the excellent term -interphase- \ve are indebted to Londegârdh 

 (12) who has applied it to the state of the nucleus during the short interval 

 between two successive mitoses in rapidly dividing tissue. In agreement 

 with the results of that author the présent study indicates that the telopha- 

 sic transformation of the chromosomes does not as a rule proceed so far as 

 in older tissue where the divisions are occurring more slowly or hâve ceased 

 altogether, and that the point reached before the prophasic changes begin 

 is by no means the same in ail nuclei. A certain degree of fine division of 

 the chromatin is apparently always necessary; just where the critical point 

 lies would be difficult to détermine in tissue showing ail stages at one time, 

 for one cannot say whether a given nucleus is still undergoing telophasic 

 change or has stopped, soon to enter upon the prophases. The nucleus of 



