CHAPTER III. — SPORES OF FUNGI. 



63 



The acrogenous abjunction of the greater number of propagative cells is either 

 simultaneous or successive. 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 

 sprouts of elongated or rounded 

 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, basidja are found which form only one spore. 



FIG. 28. Octaviaju'a carnea, Corda. Thin sections through the 

 hymenium. b, b basidia, one of them with two spores in the act of forma- 

 tion, p paraphyses. Magn. 390 times. 



FlG. 29. Basidia of Gastromycetes on their basidiophores. a basidia of Geaster hygrometricus with eight sessile 

 spores, b four-spored basidia of Lycoperdon pyriformc. 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 



