512 
Wager . — On Nuclear Division 
7. The nuclei undergo a change previous to their entry 
into the spores. They become smaller ; the outline and net- 
work become indistinct, and hardly distinguishable from the 
surrounding protoplasm. 
8. The actual entry of the nuclei into the spores was not 
observed. 
9. The observations on the colour-reactions of the nuclei in 
the various stages of division seem to point to the conclusion 
that a portion of the dissolved nucleolar substance is taken up 
into the chromatic elements, as fast as the nucleolus becomes 
dissolved. 
EXPLANATION OF THE FIGURES IN PLATES 
XXIV, XXV, AND XXVI. 
Illustrating Mr. Wager’s paper on Nuclear Division in the Hymenomycetes. 
Agaricus ( Stropharia ) stercorarius. 
All the figures have been drawn by means of the Camera lucida. 
Figures 1-8, 12-21, 23, 24 and 26-30, with Zeiss’s apochromatic 2 mm. 1.3 ap. 
and ocular 18; figures 9-1 1 and 22 and 25 with Zeiss’s apo. 2 mm. 1.4 aper. 
ocular 18. 
Fig. 1. Young basidium with two nuclei, just before fusion. 
Fig. 2. Young basidium showing the two nuclei in close contact with each 
other. 
Fig. 3. Nuclei beginning to fuse together. 
Fig. 4. Later stage of fusion, the nuclear membrane has disappeared at that 
point where the nuclei are in contact. 
Fig. 5. Later stage, complete fusion, but the two nucleoli are still distinct. 
Fig. 6. Later stage, complete fusion of all parts of the two nuclei, including the 
nucleoli. At this stage the protoplasm is very dense and deeply stained; 
vacuoles are generally absent. The nuclear network colours deep blue, the 
nucleolus dark purple or bluish red. 
Fig. 7. Basidium with nucleus in the first stage of division. The nuclear thread 
is breaking up, and the nuclear membrane has disappeared at the upper end of the 
nucleus. 
Fig. 8. Later stage of division. The chromosomes are grouped together at 
the apex of the nucleus, and now stain deeply a bright red. The nucleolus is 
smaller in size, and stains light blue. The basal portion of the nuclear membrane 
still persists. 
Fig. 9. Basidium with equatorial plate, or group, of chromosomes and 
