SARCODINA 



8i 



Clathrulina (Fig. 8). Animal enclosed in a stalked, pseudochi- 

 tinous lattice sphere; one nucleus. At binary fission, one product 

 becomes a biflagellula and swims away. In fresh waters. 



Order MYCETOZOA 



Plasmodial Sarcodina, living usually in damp places on land ; which 

 have in the active phase no shell, skeleton, or central capsule, but in 

 the quiescent phase a cyst of cellulose; possess numerous, blunt 

 pseudopodia; and are usually distributed by air-borne, cellulose- 

 coated spores. 



Fig. 73. Various stages of Chondrioderma difforme. From Strasburger. 

 A, A spore hatching. B and C, Flagellulae. D, Young and E, Older amoe- 

 bulae. F, Amoebulae fusing to form plasmodium. All x 540. G, Portion of 

 Plasmodium, x 90. nu. nucleus. 



The life history of a typical mycetozoon is as follows. The adult 

 Plasmodium is a sheet of protoplasm containing many thousands of 

 nuclei and numerous contractile vacuoles. In it there are to be seen 

 veins along which streaming takes place, alternately towards and 

 from the periphery. It feeds in a holozoic manner, usually upon de- 

 caying vegetable matter, sometimes (Badhamia) on a living plant. In 

 drought it breaks up into numerous multinucleate cellulose cysts 

 which constitute the sclerotium. It prepares for reproduction by 



BI 6 



