66 



ZOOLOGY 



SECT. 



nucleated cells (c.) connected by a homogeneous substance. In the active condi- 

 tion (A) it is produced into long delicate stiff filaments of pseuolopodial character, 

 along which the cells (c. ) travel, in the same manner as the spindles of Chlamy- 

 domyxa. Labyrinthula has, therefore, the character not of a single cell, but of 

 a cell-colony, formed of numerous cells connected together. Chlamydomyxa, on 

 the other hand, has the character of a single multinucleate cell. There is thus 

 no close connection between these two aberrant forms : but both may, perhaps, 

 best be regarded as Rhizopoda with nearer relationships to the Foraminifera 

 (Gromia in particular) than to any of the other orders. 





FIG. 50 Didymium difforme. A, two sporangia (spg. 1 and 2) on a fragment of lcaf(L), 



B, section of sporangium, with ruptured outer layer (a.) ; and threads of capillitium (/>.). 



C, a flagellula with contractile vacuole (c. roc.) and nucleus (nu.). D, the same after loss 

 of flagellum ; b, an ingested Bacillus . E, an amoebula, F, conjugation of amoebulae to form 

 a small plasmodium. G, a larger plasmodium accompanied by numerous amcebulaj; sp. 

 ingested spores. (4\fter Lister.) 



CLASS II, MYCETOZOA. 



1. EXAMPLE OF THE CLASS Didymium diffurme. 



Didymiuin occurs as a whitish or yellow sheet of protoplasm (Fig. 50, G), 

 often several centimetres across, which crawls, like a gigantic Amoeba, over 

 the surface of decaying leaves. It shows the characteristic streaming move- 



