1898 ] CELL DIVISION IN PINE SEEDLINGS 245 
EXPLANATION OF PLATES XXIII, XXIV. 
The figures were drawn with combinations of Zeiss and Bausch and Lomb 
objectives and oculars by the aid of a camera lucida, and are reduced to 
about # of their original size. The initial letter of the objectives and oculars 
are used to designate them. The four following combinatians were employed : 
Z 2™ ap. Z 18 (x 2250); Z 2™™ ap. Z 12 (X 1500); B & L yy Z 12 (x 2600); 
B& Lys, B & L }(X 1400). 
Figures 1, 16, 17, 18, 26, and 29 were taken from Pinus silvestris ; all the 
others from Pinus Laricio. 
PLATE XXIII, 
Fic. 1. Resting nucleus with large oil drops in the cytoplasm. B& L yy 
Z 12. 
Fic. 2. Resting cell, with radiating streams of cytoplasm around the 
nucleus. B&Li;; B& LP 
Fic. 3. Resting cell containing an elongated nucleus with a spindle and 
centrosome-like bodies. Z2™™ ap. Z 18. 
Fic. 4. Part of cell containing a very large nucleus in which are several 
nucleoli with vacuoles. B & L yy Z12. 
Fic. 5. Early stage of division showing first appearance of spindle. 
B&L+Z 12. 
Fic. 6. Spindle elongating showing centrosomes and radiations. B & 
L +s Z 12. 
Fic. 7. Same stage, somewhat later, showing few radiations: B& Ly 
E2. 
Fic. 8. Dome-shaped spindle showing neither centrosomes nor radiations. 
B& L +5 Z 12. 
FiG. 9. Dome-shaped spindle showing centrosomes and a few radiations. 
B& Ly Z 12. ~ ~ 
Fic. 10. Same stage more advanced. Z 2™™ ap. Z 12. 
Fic. 11. Spindle becoming pointed showing centrosomes and radiations. 
Ae aa Ape) 
Fic. 12. Spindle pointed but poles not entirely opposite. B&L+Y 
12 
Fic. 13. Nuclear membrane absent; spindle not so much pointed as is 
usual at this stage. B & L yy Z 12. 
Fic. 14. Loose mother skein stage showing appearance and number of 
chromosomes. Z 2™™ ap. Z 18. 
