226 BOTANICAL GAZETTE [SEPTEMBER 
Fic. 24.—Pinus Laricio: unusual suspensor in which third embryonal 
tube initial (e;) remained undivided, although suspensor section above it has 2 
collateral tubes; very exceptional; July 6, 1916. 
Fics. 25-27.—Longitudinal sections showing successive stages in develop- 
ment of embryo by apical cell with well marked segments; June 30 and July 5, 
14. 
Fic. 28.—Embryo about same stage as fig. 26, but with apical cell placed 
very much to one side; if section had been cut longitudinally and at right 
angles to this plane, apical cell would have been obscured; 
Fic. 29.—Very late ee in which apical cell is still active and segments 
very distinct; July 5,1 
Fic. 30.—Late stage at embryo with apical cell which has probably become 
active. and is on verge of being eliminated; July 5, 1914 
IG. 31.—Embryo smaller than fig. 29, which no beiwes possesses an 
apical cell. 
1G. 32.—Embryo past apical cell stage; July 5, 1914. 
Fic. 33.—Two successive cross-sections through the tip of an embryo 
100 «X180p,in which an apical cell may still be found; diagram 33¢ shows 
relations of segments; July 12, 1916. 
Fic. 34.—Three successive cross-sections (a, b, c) through tip of an embryo 
128 wX 280 mu (larger than any other embryo shown on this plate) in which 
apical cell may still be found, although doubtless it has become inactive; 
d, section through widest part of same embryo; e, segmentation as recon- 
structed from a, b, c; July 8, 1916 
35-—Two successive sections through tip of embryo 108 «200 p, 
showing no trace of apical cell. 
Fic. 36.—Pinus Laricio: drawing of an embryo described (8) as coming 
from splitting of a single embryo on end of a single suspensor cell, showing 
faint wall of another suspensor cell to right; it is no doubt a case where 2 
primary embryos have not completely separated and are sectioned in an 
unusual position. 
1G. 37.—T wo embryo groups of neighboring archegonia in early stage of 
* suspensor formation; apical cell of embryo to left is in mitosis giving rise to 
first embryonal tube initials; all other eee have already formed these 
cells; separation of embryos evident; June 2 
1G. 38.—Embryos of same age showing hy sccatition of the 4 primary 
embryos of each archegonium. 
Fics. 39, 40.—Successive stages in elongation of suspensors, first embry- 
onal tubes, and separation of 4 primary embryos of archegonium; June 26- 
30, 1916. 
Fic. 41.—More complete drawing of later stage with completely separated 
embryos and partly elongated embryonal tubes; one of the 4 primary embryos 
has broken loose from its attachment below and enlarged into a balloon at 
