OMPHALIA FLAVIDA 



427 



205, C, p. 408, and 214, B). These hyphae come to project aerially 

 from the gemma to a distance of 0-05-0- 1 mm., and then they cease 

 to elongate. 



When a gemma (Fig. 214, A) is placed in tap-water or in malt- 

 agar, the infection hyphae resume their growth and, in malt-agar, 

 in the course of about 24 hours, they become 0-4-0-5 mm. long, 

 thus surrounding the gemma with a radiating mycelium (Fig. 215). 

 The individual hyphae of this mycelium are evenly 

 cylindrical in form, 3-4 [x in diameter, septate, and 

 provided with numerous clamp-connexions (Fig. 216). 

 It is these hyphae which, under natural conditions, 

 penetrate through the epidermis of a Coffee leaf, 

 attack the internal leaf-tissues, and so produce a 

 leaf-spot. 



The Effect of Desiccation on the Vitality of a 

 Gemma. — It is well known that the spores of many 

 Hymenomycetes, e.g. species of Coprinus, will with- 

 stand desiccation for several weeks or months. It 

 therefore seemed of interest to enquire whether or 

 not the gemmae, which in Coffee plantations appear 

 to be the normal reproductive bodies of Omphalia 

 flavida, can also withstand desiccation. 



Some ripe gemmae were taken from the pedicels 

 of some gemmifers growing on an agar-plate and 

 they were set on four cover-glasses A, B, C, and D. 

 The gemmae on A were not allowed to dry up but, 

 immediately after removal, were covered for two 

 minutes with a minute drop of water, after which they 

 were submerged in a drop of malt-agar. The cover- 

 glass was then set on a van-Tieghem cell with water 

 at the base and the drop of malt-agar hanging down- 

 wards. The gemmae on the cover-glasses B, C, and D 



Fig. 216. — Omphalia flavida (from Trinidad). Hyphae from the 

 rswliating mycelium growing from a gemma placed in malt- 

 agar for 76 hours. As indicated by the clamp-connexions, 

 the mycelium is in the diploid nuclear condition. A, the 

 terminal part of a hypha. B, an older part of a hypha. 

 Drawn by A. H. R. BuUer and Ruth Macrae. Magnification, 

 466. 



