44 
PHARMACEUTICAL BOTANY 
During wet weather the mature antheridial wall bursts open and 
the many ciliated spermatozoids escape into the water. These mov¬ 
ing in the water are drawn by the chemotactic malic acid to the 
mouths of the archegonia of another prothallus, and, passing down 
the canal of each of these, gather around the ovum. One, probably 
the best adapted, fuses with the ovum and fertilizes it forming an 
oospore or fertilized egg. 
Origin of New Sporophyte or Diploid Plant from Fertilized Egg.— 
The fertilized egg now rapidly divides and redivides to form octant 
cells. The octant cells further divide to produce anteriorly a stem 
rudiment (one cell), first leaf (two cells), second leaf (one cell) and, 
posteriorly, root rudiment (one cell), foot rudiment (two cells) and 
hair rudiments (one cell). 
Growth of Seedling into Mature Sporophyte. —The foot rudiment 
develops into the foot which obtains nourishment from the prothal¬ 
lium, upon which the young sporophyte is for a time parasitic. The 
root rudiment becomes the first root which grows downward into 
the soil. The stem and leaves turn upward. In a few weeks the 
prothallus decays and the sporophyte is established as an independ¬ 
ent plant. More roots and leaves (fronds) are developed and ere 
long continued growth results in the formation of a mature sporo¬ 
phyte which presents for examination: (i) a subterranean stem bear¬ 
ing several roots ; and (2) cerial fronds , each of which consists of a 
stipe or petiole and a lamina or blade, the latter divisible into pinnoe 
or lobes and pinnules, upon which last sori are developed. 
Alternation of Generations. —It will be observed that in the life 
cycle of the Male Fern there occur two distinct generations, one, a 
sporophyte or asexual generation which begins with the oospore and 
ends with the dispersion of asexual spores; a second, the gametophyte 
or sexual generation, beginning with the protonemal outgrowth of 
the spore and ending with the fertilization of the egg to form an 
oospore. The sporophyte gives rise to the gametophyte which in 
turn gives origin to the sporophyte. 
