MONERA. 19 



whole, being surrounded and engulfed by the body, and the 

 protoplasmic matter is then absorbed, serving for the nour- 

 ishment and growth of the Moner. 



The simplest form known, and supposed to be really a living 

 being, is Haeckel's Protamceba. It may best be described 

 by stating that it is like an Amoeba, but without a nucleus 

 and vacuoles (or little cavities). It reproduces by simple 

 self-division, much as in Amoeba (Fig. 11). 



In Protomonas the body is very changeable in form, the 

 pseudopods often being very slender, thread-like. Fig. 8, 

 A represents this Moner during the formation of the young 

 (zoospores) in the cyst-like body, or resting-stage of the 

 creature ; B, one of these germs freed from the cyst and 

 capable of moving about by the two thread-like pseudopo- 

 dia ; C D, the Amoeba-like form which the young after- 

 ward assumes, and which at maturity passes into the en- 

 cysted or resting- stage E. 



A still better idea of what a Moner is may be seen by 

 studying the Protomyxa aurantiaca Haeckel. 



This Moner was discovered at the Canary Islands. It is 

 from half to one millimetre iri diameter, and is a perfectly 

 simple mass of orange-red jelly. When hungry numerous 

 root-shaped threads (pseud opodia) radiate from the central 

 mass. Fig. 9, E represents the Protomyxa after having 

 absorbed into its body-mass a number of shelled Infusoria. 

 When about to become encysted (A B} it rejects the shell 

 of its victims, retracts its false feet, and soon becomes fast- 

 ened as minute red balls to the surface of some dead shell. 



The ball becomes enclosed by a thick covering (A), and 

 then the contents become divided into several hundred small, 

 round, thoroughly structureless spheres, which become germs 

 (5). The germs finally burst through the cyst- wall, as in 

 C, a, c, d, and assume various monad-like and amoeboid 

 shapes, and finally attain, by simple additions of the proto- 

 plasm of its food (diatoms and infusoria), the adult form 

 (D E}. Other Moners exist in fresh water. 



We have been dealing with the simplest living forms, be- 

 ings showing no trace of organization, much lower and 

 simpler than the Amoeba, with its nucleus. The individual 



