554 Emerson : Macrophoma and Diplodia 



this way the Macrophoma spores are stained light purple and the 

 rest of the fungus brown, while the leaf-tissues become brown 

 or red. 



The Macrophoma form of this species was described originally 

 by Cooke in Grevillea (5 : 10 1), under the name Sphacropsis pal- 

 i >i arm/ 1, as follows : 



" Erumpens. Peritheciis subglobosis, applanatis, demum su- 

 perne detectis, atris; sporis ellipticis, hyalinis, intus granulosis. 

 On petioles and midribs of Cocos nucifera. Demerara. Spores 

 .02 x .012 mm. Perithecia rather large, splitting the cuticle." 



On the next page of the same paper Cooke thus describes the 

 Diplodia form under the name Diplodia epicocos : 



" Sparsa vel subgregaria. Peritheciis demum superflcialibus vel 

 semi-immersis, globosis, atris ; sporis ellipticis, uniseptatis, con- 

 strictis, brunneis. On dead young leaves of Cocos nucifera. Spores 

 .022 x .01-012 mm. Externally resembling a small Sphacria 

 of the section Denudatae." 



In the following description I have included both stages : 



Pycnidia buried to erumpent, sometimes becoming superficial, 

 black, carbonaceous, opaque, cells indistinct, 150-250/i in diam- 

 eter, subgregarious, globose or conical at the mouth ; Macrophoma 

 spores elliptical or ovoid, obtuse, hyaline, granular, 20-25 x 10//. 

 Diplodia spores elliptical, one septate, brown, obtuse, sometimes 

 slightly constricted, 20-25 x I O r i; spores borne on simple hya- 

 line sporophores 12-15 by 2-3 //, hyaline and brown spores in the 

 same way, without any order; mycelium of contorted, irregular, 

 septate threads, brown near the pycnidia and when old. 



Explanation of plate 25 



Fig. 1. Three pycnidia breaking through the epidermis of cocoanut spathe. 

 Seen from above. X 44- 



Fig. 2. The single pyenidium from Fig. 1. X 44- 



Fig. 3. Macrophoma and Diplodia spores. X 2 ^°- 



Fig. 4. Chlamydospores sprouting. X I 9 2 - 



Fig. 5. Longitudinal section through pyenidium in leaf. X I 9 2 - 



Fig. 6. Macrophoma and Diplodia spores from a hanging drop culture. 48 hours 

 old. X 28 °- 



Fig. 7. Similar to Fig. 5, more highly magnified and somewhat diagrammatic. 

 X280. 



Fig. 8. Longitudinal section of pyenidium growing above medium. X 2 %°- 



Figs. 3, 6 and 7 are drawn with a camera lucida. 



