92 



PROTOZOA 



determine the rupture of the fruit-wall and the scattering of the 

 spores. 



Again, in some cases the plasmodia themselves aggregate in 

 the same way as the amoeboids do in the Acrasieae, and combine 



/• spff.2 



cvac 



Fig. 30. — Didyniium dlffovme. A, two sporangia [spy 1 aad 2) on a fragment of leaf (^) ; 

 B, section of sporangium, with ruptured outer layer (a), and threads of capillitium 

 (cp) ; C, a flagellnla with contractile vacuole {cvac) aud nucleus (nu) ; D, tlie same 

 after loss of flagellnni ; b, an ingested bacillus ; E, an amoebula ; F, conjugation of 

 amoebulae to form a small Plasmodium ; G, a larger Plasmodium accompanied by 

 numerous amoebulae ; sp, ingested spores. (After Lister.) 



to form a compound fruit termed an " aethalium," ^ with the 

 regions of the separate plasmodia more or less clearly marked off. 

 The species formerly termed Aethalium septicum is now known as 

 Fuligo varians. It is a large and conspicuous species, common on 

 tan, and is a pest in the tanpits. Its aethalia may reach a 



' The name " aethalium " is now always used in this sense. 



