66 



DIVISION I. GENERAL MORPHOLOGY. 



In the simple successive serial or concatenate forms the abjunction is repeated 

 beneath the insertion of each propagative cell in the same direction and in the same 

 form as in the case of the first cell. If the line of abjunction in that case was broad 

 and transverse, the extremity of the sporophore beneath the youngest spore elongates 

 to a definite extent and abjunction again takes place by formation of a new trans- 

 verse wall ; if the first sprout which becomes a spore has a constricted insertion, then 

 after each abjunction a similar sprout with constricted base is developed beneath it 

 from the persistent end of the sporophore and in turn undergoes abjunction. In 

 this way a chain of similar segments is produced, in which the cells are younger in 

 proportion as they are nearer to the extremity of the sporophore from which they are 



formed. The number of cells in a chain 

 may be considerable, 20-30 or more. 

 Examples are to be found in the gonidia 

 of most of the Erysipheae, Cystopus, 

 Penicillium, Cordyceps, and the Aecidieae, 

 in the uredospores of Coleosporium, 

 Chrysomyxa, and many others (Fig. 33). 



Branched serial or concatenate forms 

 arise when one or more outgrowths stand- 

 ing side by side on the apex of a filiform 

 sporophore are abjointed, and then by 

 repeated abjunctions produce a structure 

 not unlike one of the Sprouting Fungi 

 (Fig. 3). The first sprout-cell puts out 

 one new protuberance from the apex 

 which is remote from the sporophore, and 

 this new cell and each succeeding one 

 can do the same; a row of cells is thus 

 formed in which the members are succes- 

 sively younger as the apex is approached. 

 Each of them can then form one or more 

 lateral sprouts below its apex which adjoins 

 the cell next above it, and these new cells 

 and their progeny are similar to the first 

 (Fig. 34). According as the lateral sprouts 

 on cells of successive orders are placed 



singly or in a whorl of two or more members, chains are produced in which the 

 branches vary in number and form. The cells of all orders are so many repro- 

 ductive cells which are similar to one another in all important points and become 

 ultimately detached from one another. Examples of this kind occur in the forms 

 named by Fresenius 1 and Riess 2 Periconia, in which sprout-chains are collected 

 together into a compact head at the extremity of a filiform sporophore, and in the small 

 gonidial forms of Pleospora and species of Fumago and its allies in the Sphaeriaceae s , 



FIG. 33. a Cystopus Portulacae \ m a mycelial branch bearing 

 two basidia which are producing gonidia by abjunction ; the figure 

 is further explained in the text on page 69. * Eurotium Asper- 

 ^>iilus glaucus\'r end of a sporophore covered with radiating 

 sterigmata, on which the formation of spores is just beginning. 

 j and / isolated portions showing single sterigmata pp with their 

 spores ; H youngest spore of a chain, a magn. 390, the rest 300 

 times. 



1 Beitrage. 



3 Tulasne, Carpol. II. 



Bot. Ztg. 1853. 



