PROTOZOA 9 



may be easily obtained by soaking some dried bean-stalks in 

 water for twenty-four hours, and then keeping them in a moist 

 chamber for ten days or so ; at the end of this time plasmodia 

 may be observed crawling over the stems, etc. 



The sulphur-coloured Fuligo {Aethalium) is a genus which is 

 met with in considerable masses creeping over the tan in tan- 

 yards ; others occur in rotten wood, decaying bean-stalks, and 

 dung. The spore cysts may or may not be stalked, and the pro- 

 toplasm enclosed within them does not all become spores, but 

 the remnant forms a meshwork of fibres differing in details in 

 the various genera. This network, termed a capillitium, 

 serves to support the spores, and possibly helps in their escape 

 when the surrounding wall gives way. The walls of the 

 cysts may be strengthened by the deposition of calcium 

 carbonate. The coating of the spores is of a cellulose nature : 

 a substance usually associated with the vegetable kingdom, but 

 not unknown among animals, especially amongst the Protozoa. 

 At times the plasmodia contract and surround themselves by 

 a cyst, and pass through a quiescent period. This condition is 

 known as the sclerotium. 



Myxomycetes are capable of retaining their vitality for long 

 periods of time in a dried-up condition; they resume their 

 active life again when supplied with moisture. About 300 

 species of Myxomycetes have been described, chiefly by 

 botanists, who regard these organisms as being aUied to the 

 Fungi. 



Class III. Lobosa. 



The individuals of this group are those Protozoa in whose 

 life -history the amoeboid phase predominates. The pseudo- 

 podia are lobose, thick, blunt processes of protoplasm, which 

 are never filamentous and never anastomose. One or more 

 contractile vacuoles are found, and it is stated that urates have 

 recently been demonstrated in connection with these vacuoles 

 in some Amoebae. The amoeboid individuals may conjugate 

 from time to time, but do not form plasmodia. They some- 

 times encyst, and the cyst is a resting one (hyprwci/st) and 

 not a reproductive one (sporoeyst). The usual form of repro- 

 duction is fission, which may pass into gemmation. The dis- 



