CARPOSPORE^. 
333 
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 secidium-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 hyphse of which have their apices 
Fig. i-i-i.—Puccinia Gratniiiis. A part of a vertical section of a leaf of Berberis -vulgaris with a young secidium-fruit ; 
/ section of leaf of Berberis with spermogonia and aecidium-fruits a ; p their peridium ; at *: is the natural thickness of the 
leaf which is enormously thickened between x and y; II a, mass of teleutospores on a leaf of Coucli-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 (7, 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 lo days the uredospores (///, nr), which are 
