690 
Proceedings of Boyal Society of Edinburgh. [sess. 
to induce some nucleolar expulsion during the reparation stage. 
When this material is all disposed of, the nuclear juice, when pre- 
cipitated, stains, as in the resting cell, i.e. the nucleus has become 
completely restored. I think, therefore, that one must look to the 
nuclear juice to find the earliest indication of the synthesis by 
which chromatin is built .up from simpler compounds. 
Another interesting point is the fact that so long as the nuclei 
are in an exhausted condition, no mitosis occurs, hut that as soon 
as repair has reached a certain stage a few nuclei exhibit mitotic 
figures, which increase steadily in number until the cells are 
fully restored, when its maximum is reached, to again diminish 
and cease altogether when the nuclei again become exhausted. 
Further, cells called upon to secrete during nuclear division do so 
exactly as if no mitosis were going on, and this secretion proceeds 
along with the division, both occurring at the same time, the chro- 
matin of the mitotic figure showing exactly the same changes in 
appearance and colour reactions exhibited by the karyosomes of 
the cells that are not dividing, the only apparent difference being 
that, owing to the disappearance of the nuclear envelope no 
nucleoli are formed, the split-off albuminous material being dis- 
posed of directly by the cytoplasm. 
Lastly, I would tender my thanks to the late Professor 
Rutherford for his courtesy and kindly support during the pro- 
gress of the research, and to Dr T. H. Milroy for valuable assist- 
ance in working out the chemical side of the question. 
BIBLIOGRAPHY. 
1. Balbiani, see Henneguy, Legons sur la Cellule, Paris, 1896. 
2. Bataillon, E., These doct. es Sc. Hat., Paris, 1891. 
3. Bensley, R. R., Quart. Journ. Micro. Sci., vol. xli. 
4. Carlier, E. W. , Journ. Anat. and Physiol., vol. xxxiii. p. 304. 
5. ver Eecke, Archiv. de Biol., 1893, t. 13. 
6. Flemming, W., Zellsubstanz, Kern u. Zelltheilung, Leipzig, 1882. 
7. Heidenhain, M., Festschrift fur Kolliker, Leipzig, 1892. 
8. Heidenhain, H., Pfliiger’s Archiv. , 1875, etc. 
9. Henneguy, L. F., Legons sur la Cellule, Paris, 1896. 
10. Hermann, see Henneguy. 
11. Krasser, Fr., Sitz. K. K. Akad. d. Wiss. zu Wien, 1892. 
12. Labb^, see Pizon’s Paper in Comptes Rend us, cxxvii. 
13. Langley, and Langley and Sewall, Proc. Roy. Soc. Lond., 1879 ; 
Phil. Trans. Roy. Soc., 1881 ; Proc. Roy. Soc., xxxii., 1881 ; Journ. Intern. 
d’Anatomie, 1884 ; Journ. of Physiol., vol. ii. 
