92 



PROTOZOA 



CHAP. 



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 amoeboicls do in the Acrasieae, and combine 



Fro. 30. Didymium di forme. A, two sporangia [spy 1 and 2) on a fragment of leaf (I) ; 

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

 (cp) ; C, a flagellula with contractile vacuole (c.vac) and nucleus {mi) ; D, the same 

 after loss of hagelluni ; 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," 1 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 



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



