CHAPTER 111. — SPORES OF FUNGI. 



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In basidia exhibiting successive abjunction of many propagative cells the process 

 of abjunction is repeated several times on the same basidium. There are three very 

 distinct sub-forms of successive abjunction, each of which has some special pecu- 

 liarities connected with it. These sub-forms may be distinguished as the sympodial 

 and the serial or concatenate (Reihen-weise, Kettenweise), the latter being again divided 

 into the simple and the branched. 



In the successive sympodial form (Figs. 31, 32) a single acrogenous spore is first 

 of all abjointed from the extremity of the basidium or sterigma, which is always finely 

 pointed. Then a new protuberance sprouts forth close to the point of insertion of 

 this first spore, pushes it on one side and occupies the extremity of the sporophore, 

 and is there abjointed as a new spore. A like proceeding may be repeated many 

 times ; the last spore formed is always at the apex, and its older sisters are ranged on 

 the same plane or one after another below the apex. In very extreme cases the 



FIG. 31. Dactylium macrosporitm, Fr. Extremities of spori- 

 ferous hyphae. a in a dry state with a head of spores above, b 

 in water with the primordia of the youngest spores j at the 

 extremities of the branches, the small unevennesses beneath 

 being the points of attachment of the older spores which have 

 become detached in the water. Magn. 300 times. 



FlG. 32. Botrytis Bassii, Bals. a end of a 

 young sporiferous hypha ; short lateral branchlets 

 have successively abjointed each 1-4 round spores. 

 b end of an old branch which is producing spores 

 by abjunction and is thickly covered with spores, 

 the youngest of which are terminal, c two sporo- 

 genous branches, from which all the spores have 

 fallen with the exception of the youngest and 

 uppermost, a magn. 390, b about 700 times. See 

 Bot. Ztg. 1867. 



spores are very soon entirely detached and either fall off or remain adhering only to the 

 one last formed, as happens in the formation of the gonidia of Epichloe typhina, in 

 Claviceps and in the forms known by the name of Acrostalagmus of Corda. In other 

 cases, as Botrytis Bassii and the small gonidia of species of Hypomyces and 

 Hypocrea 1 , each spore arises at least far enough above its predecessor for the points 

 of insertion to occupy some space, and the spores therefore remain united into 

 sympodial successive heads. If the spores are detached, their insertions form slight 

 projections or even short stalks at the extremity of the sporophore (Fig. 32). If the 

 sporophore were to elongate between each pair of spores a sympodial arrangment 

 would be produced, like that of Phytophthora in Fig. 20. 



1 Verticillium agaricinum and its allies, Trichoderma viride, &c. See Tulasne, Carpol. III. 

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