66 



DIVISION I. GENERAL Makl'lIOLOGV. 



In the simple successivi serial or concatenate forms the abj unction is repeated 

 beneath the insertion of ea< h propagative cell in the same direction and in the same 

 form as in the case of the firsl cell, [f the line of abjunction in that case was broad 

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

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

 verse wall; if the first sprout whi< h becomes a spore lias 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 whi< h 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 concalt nale 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 memb 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 arc similar to the first 

 (Fig. 34). According as the lateral sprouts 

 on i ells of successive orders are pl.i 

 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 5 1' i, in which sprout-chains are collected 



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

 gonidia] forms of Pleospora and species of Fumago and its allies in the Sphaeriao 



Fig. 33. a Cystopus Portulacac; m a mycelial branch bearing 

 a liiih arc producing gonidia by abju: 

 er explain 



gtaucus ; r end of a spor': red with rad 



mation of spon 



hi. a magn. 390, the n 



I 



Beitrage. 



Tula- II 



Bot. Ztg. 1853. 



