42 
PHARMACEUTICAL BOTANY 
There are two kinds of cells formed by plants, viz.: asexual and 
sexual. Both of these are endowed with the possibilities of repro- 
duction, although the former are frequently limited to the process 
of growth. 
Reproduction is the power possessed by an organism of giving rise 
to new individuals. This may take place through the agency of 
either asexual or sexual cells and is accordingly asexual or sexual in 
character. Whenever a union of cells or their protoplasmic con- 
tents takes place the process is called “sexual reproduction;” if, 
however, there is a mere separation of a cell or cells from an indi- 
vidual which later form a new organism, the process is termed 
“asexual or vegetative reproduction.” 
There are four modes of asexual reproduction, viz.: Fission, 
Gemmation, Free Cell Formation and Rejuvenescence. 
Fission. — This is the separation of a cell into two equal halves, 
each of which may grow to the size of the original parent cell from 
which it was derived. Fission is seen in the reproduction of bac- 
teria, growth of many algae and the formation of tissues of higher 
plants. 
Gemmation or Budding. — This is the method of reproduction 
common among yeasts. The cell forms a protuberance called a 
bud which increases in size until it equals the size of the cell which 
formed it and then becomes detached, although frequently not until 
it has developed other buds and these still others. 
Free Cell Formation. — This is a type of reproduction in which the 
nucleus and protoplasm become separated into two or more masses 
each of which forms a cell wall about itself. Seen in formation of 
ascospores within ascus of Ascomycetes and spores within spore cases 
of molds. 
Rejuvenescence. — In this mode of reproduction the protoplasm 
of the cell becomes rounded out, escapes by rupture of the cell wall, 
forms cilia and moves about as a zoospore. Later it looses its cilia, 
develops a cell wall and passes into a resting condition. Under 
favorable circumstances it grows into a new organism. It is found 
in CEdogonium, Ectocarpus, etc. 
There are two kinds of sexual reproduction, viz. : Conjugation and 
Fertilization. In both of these the sexual cells called gametes or 
