620 Transactions. 
heteroecious species Puccinia Caricis Schroet. is given belo 
In the early spring the teleutospore germinates and produces basidia, 
one from each cell; these grow out through the germ-pores, and, as they 
develop, the contents of the cells pass into them. Each basidium becomes 
four-celled when mature, and from each segment a sterigma is produced, 
from the apex of which a basidiospore is cut off by abstriction. The 
basidiospores are readily detached, and are carried by wind or other agency 
to leaves and shoots of plants growing in the vicinity. Should a basidio- 
spore chance to alight on a young leaf or shoot of Urtica it germinates and 
produces a short hypha, which penetrates the cuticle and enters the host- 
tissues, where it rapidly branches and forms a subcuticular mycelium, which 
soon gives rise to small flask-shaped bodies, the spermogones.f The body 
of the spermogone is embedded in the host-tissues, the neck alone pro- 
truding ; this is formed of numerous hair-like paraphyses (fig. 3) arranged 
in such a manner that a small circular or elliptical opening (ostiolum) is 
formed, through which the spermatia pass. The body is lined with hyphal 
As an illustration of the life-history of a typical rust, the cycle of the 
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Fro. 3.—Spermogone of Aecidium Ranuncularum : ; raphysis; s, spermatium. х 500. 
Fic. 4.—Aecidium of Puccinia tasmanica Diet. bod Hier lautus Fot: f.: a, peridial 
. cell; 5, peridium ; с, aecidiospore ; d, host-tissues. x 250. 
: в spermogones and spermatia are analogous to similar bodies found 
in the thallus of Collema, a genus of lichen, they were supposed to be male 
sexual organs, but as no corresponding female organ (trichogyne) has been 
* This species is taken as a type because all s i inable in 
l I pore stages are readily obtainable 1 
New Zealand. This species was first suggested by W. B. Grove (1913) as a type in 
preference to P. graminis, as the aecidia are more easily obtained. 
T Spermogones: Also known as “ spermagonia," “ pycnidia,” or “ руспіа.” 
