92 DIVISION 7. GENERAL MORPHOLOGY. 



upwards to a height of 1-2 cm., in Exoascus Pruni of i cm. ; in the strongly 

 puffing Fungi, such as Peziza vesiculosa, P. Acetabulum, Helvella crispa, and Asco- 

 bolus furfuraceus, they are thrown to a distance of more than 7 cm., in Sordaria 

 fimiseda, according to Woronin, they travel 15 cm., in the smaller species of this genus 

 about 2 cm., in Rhytisma acerinum only a few millimetres. The movements in the 

 act of puffing in large hymenia were said by Desmazieres to produce an audible 

 sound, but this has been doubted by recent observers ; I have myself however heard 

 a very perceptible hissing noise produced by strong specimens of Peziza Acetabulum 

 and Helvella crispa. 



The peculiar features in the old renus Ascobolus (including Saccobolus and others), 

 which led to many false and even strange notions, are connected with the large size 

 of the asci, the great prominence above the surface of the hymenium at the period 

 of maturity, and the regular periodicity in their ripening and in puffing 1 . Coemans 

 has given us a full account of how a number of asci ripen and eject their spores daily 

 for several days together, when the hymenium has reached 

 a certain point of development. The asci in consequence 

 of their expansion begin to appear above the surface of the 

 hymenium towards evening and continue to do so till 

 the succeeding afternoon ; between I and 3 o'clock the 

 tension reaches its highest point, and the slighest shock 

 causes ejection which is simultaneous in all the projecting 

 asci. It is difficult to determine whether ejection takes 

 place when everything around is perfectly still. The still- 

 ness is in fact always broken by a number of younger asci 

 beginning to expand every afternoon in preparation for 

 ejection on the following day. It is natural to suppose that 

 there must be a direct relation between this regular daily 

 periodicity and the light-period, and Coemans found that 

 ejection was delayed 4-5 hours in the Ascoboli, when culti- 

 vated in darkness. Boudier and Zopf observed that the asci 

 are to a high degree positively heliotropic when they are in 

 process of expansion ; their curvatures towards the source of 

 light may extend through nearly 90, but these curvatures 

 almost, if not quite, entirely disappear after ejection or 



The connection 

 investi- 

 gation. 



When the asci are ready to eject their spores they are very much extended and 

 their broad club-shaped apex rises considerably above the surface of the hymenium ; 

 this led to the erroneous idea which was reproduced by Boudier, that the asci became 

 detached from their point of insertion and wandered up between the paraphyses ; they 

 really remain firmly attached, as in all the rest of the Uiscomycetes (Fig. 45). The 

 projecting asci moreover are distinctly visible to the naked eye in the larger species 

 as dark points, by reason of the dark violet-coloured spores in their apices. These 

 points disappear at the moment of dusting, because the spores fly off and the empty 

 tubes are drawn back beneath the surface of the hymenium. Older observers were 

 led by these appearances to the mistaken notion that the entire asci were ejected from 

 the hymenium, and hence the name Ascobolus. 



FIG. 45. Ascobolus furfuractus, P. 

 Portion of a section through the hy- 



paraphyses f, a young ascus, b nearly 

 ripe ascus projecting above h h, e a 

 similar one which discharged its spores 

 during the observation and contracted r . i ^ /^ 1 1 



with an open lid at the apex. Magn. if the expansion is artificially stopped. 



195 times. between all these points requires more exact 



1 Crouan in Ann. d. sc. nat. ser. 4, VII (1857), P- T 75- Coemans. Spicilege, I (Bull. soc. hot. 

 Belg. I, i). Boudier in Ann. d. sc. nat. ser. 5, X, p. 191 



