SYSTEMATIC BOTANY. 



91 



lower animals (the Monera) that many naturahsts consider 

 them as belonging to the animal kingdom, rather than to the 

 vegetable kingdom. If they are brought to rest by absence 

 of proper moisture and temperature, they become changed 

 into rounded masses, and secrete a cellulose wall. This is 

 called the sclerotium stage. Upon return of suitable conditions 

 the Plasmodium form is again assumed. The reproductive 

 stage (Fig. 116) is also one of rest; in most of the species the 

 mass becomes compact, then 

 heaps up into definite shapes, 

 each portion becoming sur- 

 rounded by cellulose ; the pro- 

 toplasm within becomes sepa- 

 rated into multitudes of spores 

 which, in many species, are 

 commingled with an irregular 

 network of (often ornamented) 

 filaments, called the capilliti- 

 um. Under proper conditions 

 the spores burst open, the pro- 

 toplasm of each escapes as a swarm-spore with one cilium, 

 and undergoes fission (division into two equal parts by con- 

 striction). Coalescence of a number of these takes place in a 

 few days to form the new plasmodium. 



Specimens of the vegetative stage {plasmodium) of the Slime-moulds are 

 difficult to find except in a few species where the mass is very large, as in 

 " Flowers-of-tan," sometimes seen on spent tan-bark, on piles of rotten saw- 

 dust or on rotten stumps in damp woods. But specimens showing the repro- 

 ductive stage may be found on rotten logs, stumps, etc. in damp shady 

 woods. The pocket lens will reveal some of the characters mentioned in the 

 text, but of course they cannot be exhaustively studied without a compound 

 microscope. Illustrative specimens can be glued to herbarium sheets, or 

 preferably put in paper pockets or small pill-boxes. 



8. The Bacteria are representatives of the group Schizo- 

 phytes. They are exceedingly small (in some cases no more 

 than one twenty-thousandth of an inch broad) and simple 

 organisms destitute of chlorophyll (Fig. 117). They occur 



Fig. 116. 



