fHIELAVIOPSIS PARADOX A. 535 



The Colour of the Spores. 



The differences in the recorded colours of the spores, as 

 described by different observers, are at first somewhat 

 bewildering. de Seynes states that the microconidia are 

 hyahne, and the macroconidia ohvaceous brown, black in 

 mass ; but he notes that some of the microconidia assume the 

 colour of the macroconidia. Went (8) gives the microconidia 

 as colourless, sometimes slightly coloured, and the macro- 

 conidia as dark oUve-green. According to Massee (6) the 

 microconidia are pale reddish-brown, while the macroconidia are 

 clear olive-green, then sooty-brown, and finally opaque blackish 

 brown. PrilUeux and Delacroix (7) state that the micro- 

 conidia are hyaline and the macroconidia black. Howard (10) 

 states that the microconidia are hyaline, then reddish-brown, 

 and the macroconidia sooty black. V. Hohnel (12) regards the 

 supposed two forms as identical, the final colour being brown. 

 Cobb (14) states that the microconidia are nearly colourless, 

 sometimes darker, and the macroconidia brown or blackish. 



With one possible exception, all these colours are correct 

 at some stage or other. The microconidia are at first hyaline, 

 then fuliginous, tlien almost black, while the macroconidia 

 are hyaline, then clear gi-een or ohve-green, then greenish - 

 black. They are black in mass. If they are left lying in the 

 culture medium, or if they are dried, or preserved in alcohol, 

 or mounted in glycerine, they become blackish-brown. I have 

 never been able to detect any pronounced reddish tint. 



Similar cases are not uncommon among the Phceosporce. 

 The extruded spores of Botryodiplodia theohromce, for example, 

 are hyaline when the substratum is dry, and they remain 

 hyaline for a long period ; sent to Europe from America in 

 this condition, the fungus was re-named Macrophoma vestita. 

 In fresh pycnidia of the same species, the spores may be 

 grayish, or greenish -black, or violet-black. But old spores, 

 whether preserved dry or in alcohol, are blackish -brown, 

 black in mass. 



The Order of Occurrence. 



The spores which are formed within the decaying tissues of 

 sugar cane or coconut are apparently always macroconidia. 

 If tlie diseased tissue is cut and kept damp, microconidiophores 



