191 



(212) ■ furrowed etalks of which are broadenea at the top like th© 



head of a anil, ana closed by flatly convex, smooth apical 

 snrfr;oos". The fvingtia forms its spores in this part of 

 the ©xoBescence - the "fruit -galls". These fruit -galls 

 shor a certain similarity to prosoplasmas (the size-propor- 

 tlonB seen to vary); because of their characteristic foim 

 and still more in their peculiar differentiation. Such an 

 one is produced by the outgrowth into long filaments of thB 

 cells of the host plant, lying at the fruiting " spot of the 

 fungus, Solraa-laubaoh compares these filaments, In their fom 

 and function, --dth the fibres of the myxomyeetes-capillltia* 



Still another fungus gall, closely 'related to proso- 

 Ei'^i?^*}® S^^^^» despite its simplicity, is that produced 

 ??oJ!i® ■^S^^®^ °? ?^-:fc g^^ill^-^^ ornientilla • bv S;mchytrlum plll- 

 rioum, Here and IWre ar® formed small, roundisir.~^lc^pro"- 

 tubetences V7hich are beset over and orer again with very 

 long, unicellular thick-walled hairs. All gall lndividi\als 

 are equally large and similarly formed. The small gall, 

 Which seems to be pretty rare, is of especial interest J- be- 

 cause through it -.vas Illustrated the relartions ^feloh were ©x~ 

 ^5 X® ^to'i^e, between constancy (and variability) of form 

 rsi«5> $4 ,! ® constant (or changing) extent of the stimulatory 



««A^>/ field. The infecting organian does not extend beyond its 



nutritive cells; the field of stimulation is therefore al- 

 ways of uniform size. Also the developmental period of the 

 parasite and the ch&raoter of the stim[ulation varies In the 

 Synchytrlae within narrower limits than in many other fungi, 

 which produces galls. Figure 80 explains the histology of 

 the gall. In the centre is the nutritive cell, adjacent to 

 it the parenchyma, and the epidermis with its many hairs, 

 distinguished from normal ones by their size and the den- 

 sity of their growth. 



In the following, we will first report on the external form 

 and the course of development of the prosoplasmas and later in- 

 vestigate more cloeely the histological details of their develop- 

 ment and the structure of the matured gall. 



1* External Form and Course of Development of Prosoplasmas 



She external form of galls varies greatly. In all cases they 

 display extensive manses of tissue, v;hich enclose a more or less 

 spacious hollow cavity, in which the gall animals remain. While, 

 in kataplasmas, the animal parasites live superfioie,lly or in 

 cavities imperfectly closed, as in leaf roll galls, the proso- 

 plasmatic galls are chp-racterized by well enclosed cavities of 

 definite form, 



Prosoplasmas may be subdivided into four groups according 

 to their form and course of development^. 



1, The simplest prosoplasmas are produced by the turning 

 down or inrolllng of the edge of the Infected leaf/ A "leaf 

 fold gall arises, which bears a marked similarity to many kata- 

 plasmas already named. A compa.rison of prosoplasmas and kata- 



■^ Thomas, Fr,, Synchytrlum pilificum . Ber, d. D. B«t. Ges, 

 1883, Bd, 1, p. 494. I owe the herbarium material to the kind- 

 ness of Professor Thomas (Ohrdruf). 



^ Compare here Kerner Pflanzenleben, 1898, Bd. II. 



