CHAPTER III-—SPORES OF FUNGI. 63 
The acrogenous abjunction of the greater number of propagative cells is either 
simultaneous or suecessive. It is simultaneous when a number of shoots make their 
appearance at the same time at the apex of the basidium, grow with the same rapidity, 
and experience abjunction at the same time, either at their point of insertion or beneath 
their apex which is borne by the stalk (sterigma). The protoplasm of the basidium 
is used up in the process and is not again renewed. Simultaneous abjunction is 
especially characteristic of the 
basidia in the hymenia of most 
Basidiomycetes (Hymenomyce- 
tes, Gastromycetes (Figs. 28, 29), 
Calocera, Dacryomyces). The 
basidia in these are generally 
club-shaped terminal cells of hy- 
phal branches, and spores are 
abjointed at their broad apices, 
usually as the extremities of long 
sterigmata, more rarely as sessile FIG. 28 Octaviania carnea, Corda. Thin sections through the 
hymenium. 4, 5 basidia, one of them with two spores in the act of forma- 
sprouts of elongated or rounded tion,  paraphyses. Magn. 390 times. 
shape, as in Geaster hygrome- 
tricus, Scleroderma, Polysaccum, and Phallus. The number of spores is in the 
large majority of cases 4 to each basidium, in some cases 2, as in Calocera, 
Dacryomyces, some species of Hymenogaster and Octaviania, in a few cases 6-9, 
as in the Phalloideae, Geaster, and Rhizopogon. Slight variations from these regular 
numbers are not unfrequently found, especially in the species which do not form 
four spores on each basidium; in the Hymenogastreae, as in Hymenogaster 
Klotzschii, basidia are found which form only one spore. 



Ad 
FIG. 29. Basidia of Gastromy on their basidi @ basidia of Geaster hygrometricus with eight sessile 
spores. @ four-spored basidia of Lycoperdon pyriforme. c four- to eight-spored basidia of Phallus caninus. Magn. 
390 times. 
Outside the group of Hymenomycetes basidia which produce many spores 
simultaneously occur in a great variety of forms on many gonidiophores, as in Peziza 
Fuckeliana, Botryosporium, Haplotrichum, and Gonatobotrys. The number of spores 
abjointed is normally higher in such cases than in the Basidiomycetes ; they are usually 
placed close together on short stalks, so that we may speak of spore-heads formed 
simultaneously. ‘The typically unicellular branches of Peronospora which abjoint 
gonidia may be included with the above, especially if we take into consideration the 
form distinguished by Cornu under the name of Basidiophora. 
The simultaneously plurisporous basidia of the Basidiomycetes are usually more 
or less broadly club-shaped before the formation of spores, as has been already 
