FIXATION OF SPORES IN THE ASCUS 247 



the ejected spores placed end to end, one behind the other, so as 

 to form a continuous chain. It is highly improbable that a group 

 of ejected spores should form such a chain if they were not really 

 attached together. 



When a section through the hymenium of Peziza repanda is 

 mounted in water, the asci are fully turgid. If such asci are 

 caused to explode by bringing a solution of iodine into contact 

 with them, the spores are discharged to a distance from the ascus 

 mouths about equal to the length of the asci. When vigorously 

 discharged in this manner, the eight spores are shot out so quickly 

 that one can see nothing of them as they pass through the fluid 

 medium. The eight spores suddenly come into sight in front of 

 the ascus which has discharged them. They are then not travelling 

 horizontally but merely sinking in the fluid. On their first appear- 

 ance they are all separated from one another in the manner represented 

 in Fig. 79, H. The very transparent, unilateral, gelatinous cap on 

 each spore then swells up considerably, doubtless owing to the 

 absorption of water. Running down the middle of each cap is 

 a row of granules, which are doubtless the same as those shown 

 in Fig. 79, E, and therefore the remains of the suggested extension 

 of the protoplasmic bridle over the spores. 



The attachment of the eight spores of an ascus to one another 

 in Peziza repanda is not a firm one like that in Ascobolus imniersus 

 (cf. Figs. 81 and 82), but only a very loose one just strong enough 

 to hold the spores together before discharge, and therefore of use 

 in aiding them to take up a favourable position in the ascus, 

 but weak enough to be easily broken down at the moment when 

 the ascus ejects its contents. In all probability, the snapping of 

 the spore chain* into eight parts is due to the different spores 

 receiving different velocities during their ejection, and takes place 

 as the ascus jet is elongating whilst leaving the ascus mouth. 



One further point concerning the spores of Peziza repanda 

 may here be mentioned. When a fruit-body is confined in a 

 small closed chamber, many of the spores, after being cast up 

 into the air, fall back again on to the hymenium. Under moist 

 conditions such spores often germinate and produce conidia, as 

 shown in Fig. 79, I. 



