128 ELEMENTS OF BOTANY. 
germination the spore swells as shown at } and then bursts, 
discharging its protoplasmic contents, as seen at ¢ and d. 
This in a few minutes lengthens out and produces at one end 
a hair-like ciliwum, as shown at e, f, g. These ciliated bodies 
are called swarm-spores, from their power of swimming freely 
about by the vibrating motion of the cilia. Every swarm- 
spore has at its ciliated end a nucleus, and at the other end 
a bubble-like object which gradually expands, quickly dis- 
appears, and then again expands. ‘This contractile vacuole is 
commonly met with in animalcules, and increases the likeness 
between the slime-moulds and many microscopic animals. 
The next change of the swarm-spores is into an Ameba-form 
(so-called from one of the most interesting and simplest of 
animals, the Amewba, found on the surface of mud and the 
leaves of water-plants). In this condition, as shown at h, i, 
k, the spores creep about over the surface of the decaying 
vegetable material on which the slime-moulds live. Their 
movement is caused by a thrusting out of the semi-liquid pro- 
toplasm on one side of the mass, and a withdrawal of its sub- 
stance from the other side. At length many amceba-shaped 
bodies unite, as at 2, to form a larger mass, m, which finally 
increases to the protoplasmic network shown at 2. This 
eventually collects into a roundish or egg-shaped, firm body, 
inside of which a new crop of spores is produced. It is not 
easy to trace the manner in which the nourishment of these 
simple plants is taken. Probably they absorb it from the 
decaying matter upon which they live during their ameba- 
like period, and after they have formed the larger masses, 2. 
:162. Characteristics of Living Protoplasm.1— The behavior 
of the slime-moulds during their growth and transformations, 
as just outlined, affords a fair idea of several of the remark- 
able powers which belong to living protoplasm, which have 
been summed up as follows : 
1 See Huxley’s Essays, vol. I, essay on ‘‘ The Physical Basis of Life.” 
