SPERMATOPHYTES—GYMNOSPERMS 
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Fig. 102 .—Pinus Laricio: photomicrograph showing the formation of the ventral canal cell; 
usually this cell is not so large in proportion to the egg; fixed in Flemming’s weaker solution and 
stained in safranin, gentian-violet, orange; the preparation was made in 1897, the photomicrograph 
in 1915; Cramer contrast plate; 4-mm. objective; ocular X4; Abb§ condenser; yellowish-green 
filter and also a strong filter used in outdoor photography; camera bellows, 75 cm.; arc light; 
exposure, 7 minutes. Negative by Miss Ethel Thomas. X587. 
and sperm nuclei occurred about a week later, and stages like Figure 
1015, C, and D, were common in material collected July 2. In the 
season 1896 all the stages appeared about 2 weeks earlier. In Pinus 
sylvestris the stages appeared a little earlier than in Pinus Laricio. 
the megaspore mother-cells appear as soon as the young strobili 
break through the bud scales. At Chicago, in the season of 1897, 
material collected May 27 did not yet show archegonia; the ventral- 
canal cell was cut off about June 21 (see Fig. 102), the fusion of the egg 
