128 ELEMENTS OF BOTANY. 



germination the spore swells as shown at b and then bursts, 

 discharging its protoplasmic contents, as seen at c and d. 

 This in a few minutes lengthens out and produces at one end 

 a hair-like cilium, as shown at e, f, g. These ciliated bodies 

 are called swarmrspores, 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 Amoeba-form, 

 (so-called from one of the most interesting and simplest of 

 animals, the Amoeba, 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 I, to form a larger mass, m, which finally 

 increases to the protoplasmic network shown at n. 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 amceba- 

 like period, and aJEter they have formed the larger masses, n. 

 162. Characteristics of Living Protoplasm} — 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 protpplasm, which have 

 been summed up as follows : 



> See Huxley's Essays, vol. I, essay on " The Physical Basis of Life." 



