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RESEARCHES ON FUNGI 



through a right angle. At c is a basidium discharging its first 

 spore which is carrying a drop of water with it through the air, while 

 another spore has a drop of water of maximum size at its base and 

 is about to be discharged. At d is a basidium which has discharged 



all its spores save one : the spore 

 being projected forwards through 

 the air is carrying its drop of water. 

 From e all the spores have been 

 discharged while at // basidia are 

 shown which have collapsed shortly 

 after spore-discharge. At g and h, 

 the trajectories of three spores in 

 still air are shown by arrows. The 

 distance due to the force of pro- 

 pulsion is only represented as being 

 0-3 mm. in g and 0-28 mm. in h, 

 owing to want of space ; but, as we 

 have seen, spores are projected 

 farther than this, often twice the 

 distance shown at g and h {cf. Fig. 

 214, p. 534). By glancing around 

 the Figure at d, i, c, h, e, and g, it 

 will be seen that the spores, owing 

 to their development on the convex 

 side of the curved basidia, are 

 discharged more or less radially 

 outwards from the sorus centre. 

 The advantage of the curvature of 

 the basidium and of the spores 

 being developed on the convex side will now be obvious. There is 

 no doubt that the shape of the basidium favours effective spore- 

 dispersal. If the spores were developed on the concave sides of the 

 basidia instead of the convex, very few of them could escape. 



It was found that some of the teleutospores in a compressor 

 cell were germinating in a film of water condensed on the cover- 

 glass. Under these conditions the basidia became unusually long 

 and their ends became broken up into what Eriksson has called 



Fig. 217. — Puccinia Malvacearum. 

 Development of basidia in a film 

 of water. A section of a teleuto- 

 spore-sorus from a Hollyhock 

 leaf was placed in a compressor 

 cell. The basidia here shown 

 grew outwards in a film of water 

 on the cover-glass. A, a teleuto- 

 spore with two basidia : one of 

 these has produced three end- 

 conidia and the other, one. B, 

 a basidium with three end- 

 conidia ; C, one with four ; and 

 D, one with four and a possible 

 fifth. Magnification, 293. 



