30 Paraphyses. 



ilry, they would be required in much larger numbers. The presence or 

 absence of paraphyses at different periods of the year seems to have been 

 only definitely observed in this one species, but there are other instances 

 which may possibly belong to the same category. Thus Winter describes 

 Uromyces dactylidis Ot-th. with capitate thickened paraphyses, and Plow- 

 right distinctly states that they are absent, and this discrepancy may arise 

 from the observations having been made at different seasons of the year. 

 Again, Puccinia pomum Niels, is without paraphyses, according to Plow- 

 right ; but Schroeter found them in Germany, and I have found numerous 

 long ones in Australia. In P. magnusiana Koern. the clavate paraphyses 

 are of a dark smoky brown colour in the head and hyaline in the stalk. 

 They only occur at the margin of the uredo-layer, and there is a slight 

 indentation on the inner side, so that the head bends over. In Phragmi- 

 dium subcorticium the tubular, thin walled paraphyses are always mar- 

 ginal both in the uredo- and aecidio-spore generation, and are curved 

 inwards. 



Another function has been suggested by Magnus 6 in addition to \that 

 of protection. In several species of Coleosporium he found that the 

 paraphyses served both for protection and for raising and bursting the 

 epidermis so as to make room for the growing spores. 



To a certain extent paraphyses may assist in raising the cuticle and 

 hastening its rupture; but there are plenty of species which rupture the 

 cuticle in the absence of paraphyses, and in the case of paraphyses asso- 

 ciated with teleutospores, they rather appear to prevent the cuticle break- 

 ing away until it decays. 



