EU-MYCETES.— (^;) BASIDIOMYCETKS 



aa: 



but, being the product of a reduction-process, they niiglit properly be 

 called carpo-spores (Fig. 381, 5, s). Their peculiarity is tliat they (i<, 

 not cause infection on the Wheat, but can penetrate the epidermis 

 of the Barberry. Acting on the suspicions already aroused, the 



Fig. 382. 

 Sporidia, or carpospores, of Puccinia, germinating on the epidermis of a Barberry 

 leaf, and putting out germ-tubes, which bore through the cell-walis. \itv hiehlv 

 magnified. (After Marshall Ward.) 



infection was first made by De Bary in 1864. He found that the 

 carpospores easily shed from the sterigmata germinate to form a 

 germ-tube, which can directly penetrate the epidermal wall of the 

 Barberry (Fig. 382), This initiates the second phase, and as the 



1 



Fig. 3«3- 

 Vertical section through a patch of aecidia (cr) and sponnogouia (j) on the 

 Barberry leaf, showing the swelling of the diseased part. The small aecidtiiin 

 to the right {a) has not yet biurst. Highly magnified, (.\ftcr Marshall Ward » 



carpospore itself was haploid, so is the stage prodnrc.l fmni it en 

 the Barberry. Each cell has only a single nucleus. 



A section through an infected spot on the Barberry k-.il s\\o\\ 

 effect of the attack in the greatly increased thickness xs comj-.:' 

 with the normal leaf (Fig. 3'^3)- 'l^'^^^ enlarged crils of the me?ophyll 



