CHAPTER III.—SPORES OF FUNGI. 65 
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 szmple and the branched. 
In the swecessive 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 macrosporum, Fr. Extremities of spori- “ FIG. 32. Botrytis Bassii, Bals. a end of a 
ferous hyphae. a ina dry state with a head of spores above. 5 young sporiferous hypha; short lateral branchlets 
in water with the primordia of the youngest spores s at the have successively abjointed each 1-4 round spores. 
ext ities of the b hes, the small beneath 6 end of an old branch which is producing spores 
being the points of attachment of the older spores which have by abjunction and is thickly covered with spores, 
become detached in the water. Magn. 300 times. the youngest of which are terminal. ¢ two sporo- 
genous branches, from which all the spores “have 
fallen with the exception of the youngest and 
uppermost. @ magn. 390, 5 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', 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. zo. 

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