Gh eed Sey hh ee 2 atl EIN Ee aed, SNe ee ae 
1897] LIFE HISTORY OF LILIUM PHILADELPHICUM 421 
embryo sac enlarges rapidly except at the antipodal end, which 
is left as a sort of caecum, often thrust to one side, in which may 
be seen the disintegrating antipodal nuclei (fg. 35). Around 
the narrowed antipodal end of the sac there is developed a very 
heavy wall, which in itself would seem to be a sufficient reason 
for the failure of that region of the sac to enlarge. 
EXPLANATION OF PLATES XXXII-XXXIV. 
figures are reduced from drawings to about three-eighths of their 
original size. The combination of objective and ocular is indicated in 
each case, the initial letters indicating Zeiss, Leitz, Reichert, and Bausch and 
Lomb. The four combinations used and their magnification in diameters 
were R+ R4, 760; B & Ly immersion R4, 1200; Z+y immersion L4; Z 
immersion Z18, 2250. All the figures are from Lilium Philadelphicum 
unless otherwise indicated. 
1. Tip of nucellus with the oo archesporial cell which develops 
Pes into the macrospore. B& Ly; R 
Fie. 2. First division of the macrospore hers showing radiations about 
the daughter nuclei, and thickening of spindle fibers in the equatorial region. 
Zr Ly. 
Fic. 3. Daughter nucleus of the first division at an earlier stage, showing 
relation of micronucleoli to radiations. Zs Z18. Iron alum. 
Fic. 4. Spindles of the second nuclear division of the macrospore, show- 
ing transverse axis and reduction number of chromosomes of micropylar 
Spindle, and longitudinal axis and increased chromatin mass of the antipodal 
Spindle. Zj, L4. Iron alum. 
Fic. 5. Spindles of the second division. Zp; L4. Iron alum. 
Fic. 6. The four nuclei of the second division completed. Zyy L4. 
Figs. 7~7a. The four nuclei, showing persistence of spindle ‘fibers and 
shifting of nuclei. B& Lys R4. 
Fig. 8. The four nuclei much shifted. B & Liy R4. a 
Fic. 9. An unusual antipodal spindle, a several iste and continu- wee 
ous looping of chromatin band. Zy Z18. 
Fig. 10. The micropylar spindle of the pes sac, howe mou poles | 
and two masses of continuous looped chromatin band. Zt Z18. Iron alum. 
ES “Fig. 11. Eo Sain eee som see padi — 
erythrosin. 
_ Fic. re pete cay! spindle of same sac, showing seve pes anacon a 
