184 EEV. K. ABBAT 0?f HEXTSIIA VASTATRTX. 



is not the case. The former suffers to very nearly the same 

 extent as the cultivated tree ; whilst the latter showed that it was 

 susceptible to the "disease" by being badly attacked within a 

 few months after the first plants of the species were introduced 

 into the island. 



DESCRIPTION OF THE PLATES. 



Plate XIII. 



Fig. 1. " Disease " spot in process of development, the immature sporanges 



being orange-coloured, whilst the more mature are almost colourless ; 

 the dark spot in the centre is due to the presence of a black aspergillus ; 



half natural size. 



2. Portion of the cuticle of a diseased coffee-leaf, showing clusters of spo- 



ranges and stomates ; X 150. 



3. The same piece of cuticle, seen from the inside ; X 150. 



4. Cluster of sporanges with the dark mass that bears them and mycelium 



extricated from the leaf; X 200. 



5. 6, 7. Mycelium from the interior of a " diseased n coffee- leaf ; X 350. 

 8, 9. Cluster of sporanges from which all the more mature sporanges have 



been washed ; X 400. 



10. Cluster of sporanges from Sumatra, showing the barren cyst-like bodies 



amongst them ; X 250. 



11. The same as fig. 10, treated with potash and subjected to pressure; 



X 250. 



1 2. Barren cyst detached by pressure. 



Plate XIV. 



Fig. 1, 2. Sporanges with portions of pedicel attached ; X 800. 



3. Sporange, showing the spores in its interior ; X 800. 



4, 5, 6. Spores detached by pressure from the sporange ; X 1000. 

 7, 8. Spores attached to portions of ruptured sporanges ; X 1000. 



G00 



10. Spores germinating within or near the sporange ; X 600. 



11, 12, 13. Somewhat immature and mature spores germinating; X 1000. 

 14, 15. Mycelium produced by germinating spores; X 500. 



16. Mycelium with the commencement of the conidioid form of fruit ; 



X 700. 

 Well 



1000 



gments 



19, 20. Conidioid forms of fruit. Fig. 19 x 500; fig. 20 X 1000. 

 21. Conidium germinating : X 1000. 



