CARPOSPOREM. 



3,3,3 



gonium is covered with short mycelial branches, from the ends of which are detached 

 numerous very small spore-like bodies, the Spermatia. It has already been stated that 

 their significance in the development of the Fungus is unknown. The aecidium-fruits 

 lie at first beneath the epidermis of the leaf, where they form a tuberous parenchymatous 

 body {A), also surrounded by an envelope of fine mycelial filaments. When mature the 

 aecidium breaks through the epidermis of the leaf and forms an open cup, the wall of 

 which (the peridium, p) consists of a layer of hexagonal cells arranged in rows, which 

 are produced at the bottom of the cup from basidium-like mycelial branches. The 

 bottom of the cup is occupied by a hymenium, the hyphae of which have their apices 



Fig. 223. — Puccinia Grattwns. A part of a vertical section of a leaf oi Herberts vulgaris with a young secidium-fruit ; 

 / section of leaf of Herberts with spermogonia sp and aecidium-fruits a ; p their peridium ; at ^ is the natural thickness of the 

 leaf which is enormously thickened between x and y; II & mass of teleutospores on a leaf of Couch-grass ; e the ruptured 

 epidermis; b the hypodermal fibres; t teleutospores; /// part of a mass of uredospores ur with one teleutospore t; 

 sh sub-hymenial hyphae {A and / from nature ; // and /// after De Bary). 



directed outwards and are continually detaching new conidia-like spores, which, originally 

 of a polyhedral form in consequence of pressure from opposite sides, afterwards become 

 rounded, and separate from one another at the opening of the cup (/, a). The peridium 

 itself has the appearance of a peripheral layer of similar spores ; its cells however remain 

 united, and, like the spores, contain red granules. The aecidiospores produced upon 

 the leaves of Berberis only develope a mycelium when their germination takes place 

 upon the surface of a leaf or stem of Grass (as Wheat or Rye). The germinating fila- 

 ments then penetrate through the stomata, and the mycelium produced in the paren- 

 chyma of the Grass generates within 6 or 10 days the uredospores (///, «r), which are 



