4 THE ORIGIN OF PLANT AND ANIMAL CHILDREN 
Buds and Shoots. — The yeast we put into bread dough is 
composed of small cells. A projection called a bud forms at 
the side of the cell. It grows until it becomes nearly as large 
as the parent, when it breaks off and becomes a new individual. 
Reproduction by budding is very common also among 
animals of the lower groups (coral, moss-like 
animals, and others), but in these cases the 
bud at the side of the animal is composed of 
many cells. A great many plants send out 
shoots or branches, under ground or above, 
which at certain places form roots and stems, 
thus making new individuals. Gardeners 
cut slips from plants and put them in the 
moist soil, where they develop roots and be¬ 
come separate plants. 
Figure 5. — A 
Yeast Cell 
with Three 
Buds. 
1. Name several plants and animals which reproduce by means 
of buds. 
2. What plants have you seen propagated by slips, cuttings, 
runners, or other asexual methods ? 
In asexual reproduction the offspring is just like the parent, 
is simply a part of the parent’s body which has been sepa¬ 
rated from it and acquired an individuality of its own. This 
method of reproduction is found in nearly all plants and is 
common in the lower groups of animals. 
Sexual Reproduction. — Sexual reproduction is a complex 
process, in contrast to the simple asexual method, and the 
new feature, which makes it so different from the asexual 
process, has deep meaning and far-reaching influence. 
Spirogyra. — The reproduction in spirogyra may be taken 
to illustrate the simplest form of sexual reproduction. This 
little plant, found in fresh-water ponds, consists of a thread 
composed of cells placed end to end. At times two threads 
lying near each other send out projections which join and 
form a channel through which the protoplasm of one cell 
