CuxxiNGHAM.—T'he Uredinales, or Rust-fungi, of New Zealand. 691 
observed in the Uredinales they were considerd to be functionless. Although 
they do not germinate when placed in water, Cornu showed that when 
placed in a weak sugar-solution the spermatia germinated readily, and 
produced a short hypha, which is but short-lived. The production of this 
hypha shows that, whatever the function of spermatia may be, it is not a 
sexual one; moreover, all experiments made with a view to ascertaining 
whether they will infect the host plant (and thus behave like conidia) have 
proved fruitless. 
Shortly after the production of spermogones accidia make their appear- 
ance. typical aecidium consists of an outer peridium enclosing the 
central mass of aecidiospores (fig. 4). he peridium is at first globose 
and deeply immersed in the host-tissues, but owing to the gradually 
increasing pressure of the developing aecidiospores it becomes more or less 
until the Бене extends some distance beyond the leaf-surface (Plate 77, 
fig. 1). Тһе peridium is formed of irregularly hexagonal cells, whose inner 
surfaces are usually strongly sculptured (text-fig. 4, a). The peridium 
encloses the aecidiospores ; these are produced in acropetal succession from 
basidia seated on the floor of the peridium; they are catenulate, and in 
young aecidia each spore is separated from its neighbour by a small com- 
pressed ОТЕ cell which soon disappears, so that its presence is often 
difficult to prove. The mature spores are at the top of the peridium, and 
as they are Е others are forced into their place by the pressure 
of the developing — below. Each spore is, as a rule, polygonal, owing 
to the pressure to w it has been subjected whilst within the peridium, 
and consists of an «бар, which is usually colourless, finely verruculose, 
and perforated by numerous obscure germ-pores, and granular contents 
brightly coloured by an oil which serves as reserve food. Generally 
aecidiospores remain viable but a short time, though cases have been 
recorded where they have germinated after a period of two months. In 
many species the mycelium is perennial and produces aecidia season after 
season; the presence of a perennial mycelium is usually indicated b 
distortion and yellowing of the host plant (Plate 77, fig. 2). Аесійіоврогез 
may give rise to further generations of aecidia on the same host, or may 
produce the next spore-stage in the cycle. 
Should an aecidiospore alight on the leaf of Carex, if conditions are 
favourable it germinates and “produces a single germ-tube (rarely more), 
which grows out through one of the rand spe As the germ-tube wet bie v 
each hypha small haustoria are given off ; these penetrate into the тонат 
cells and absorb the food substances necessary for their continued existence. 
The hyphae continue to develop rapidly until hyphal masses (mycelium) 
are formed immediately beneath the epidermis of the hos m 
mycelium vertical hyphae are given off, on the apices of which small 
rounded cells are formed ; these cells divide into two, the upper cell forming 
the uredospore, the lower the pedicel on which the uredospore is borne. 
By the pressure of these developing spores the epidermis becomes forced 
