138 BOTANICAL GAZETTE [AUGUST 
PLATE VII, 
Fics. 83-90. Successive stages in division of central cell of archegonium ; 
Jigs. 83-89. X 800; fig. 90. X 280 
Fic. 91. Group of archegonia after formation of ventral canal nuclei. 
F1G. 92. Two archegonia of same group slightly more magnified. X 70. 
FiGs. 93-96. Neck cells seen from above. X 400. 
Fics. 97-98. Surface view of megaspore wall showing pits; after forma- 
tion of young prothallium. X 800. 
FIG. 99. Pits of same wall in section. X 800. 
PLATE VIII. 
FiG. 100. Sperm cell just entering cytoplasm of archegonium tip; its 
nucleus barely visible in dense starch sheath around it. x 
Fic. to1. Sperm cell protoplasm just touching egg nucleus; sperm 
nucleus not yet in contact with egg nucleus. X 800.. 
Fic. 102. Sexual nuclei in contact; sperm cell protoplasm beginning to 
inclose the egg nucleus. X 400. 
Fic. 103. Later stage of fusion. X 400. 
FIG. 104. Supernumerary sperm cell in tip of archegonium. X 400 
Fig. 105. Later stage of ip starch sheath completely inclosing the 
not yet entirely fused nuclei. 
Fig. 106. Archegonium at age uss above ; fusing nuclei moving down 
and a. vacuole broken up. X 70. 
Fig. 107. Egg and ventral canal nucleus in tip of an archegonium that 
did not ee fertilized. x 280. 
Fic. 108. Ventral canal nucleus at tip of an archegonium of same group 
as above a has been fertilized and hasa two-celled embryo in the base. 
280. 
FIG. 109. Ventral canal nucleus in another fertilized archegonium of 
same group; it has grown out into the protoplasm and is beginning to divide 
amitotically. x 280. 
Figs. 110-112. Successive stages in growth of ventral canal nucleus in 
fertilized archegonia ; all with young embryos in base; extra sperm cell lying 
in tip of archegonium in I10. X 400. 
PLATE IX. 
Figs. 113-114. Ventral canal cells in archegonia that missed fertiliza- 
tion; others in group have been fertilized. x 280. 
Fic. 115. Amitotic division of ventral canal nucleus. X 400 
Fic. 116. Archegonium with 8-celled embryo at base ; spille are formed 
between the cells, but upper cells open above; here there are seven cells in 
upper tier and only one below; canal nucleus at tip; disorganized layer 
above embryo. x 400. 
