392 MANUAL OF FRUIT DISEASES 
and related plants like the juneberry, hawthorn and apple. 
But in order to complete the life-history it must have the red 
cedar, or juniper (Juniperus communis and J. virginiana). 
On the red cedar twigs there are produced peculiar canker-like 
Fig. 116. — Quince-rust on 
red cedar. 
lesions (Fig. 116). These diseased- 
spots begin their development in 
midsummer. The fungus hibernates 
within the twig as mycelium. With 
the advent of the first warm, moist 
spring weather the fungus resumes 
growth and development. On the 
surface of the affected area numerous 
yellow, gelatinous masses appear, — 
the teliospores of the fungus. Each 
teliospore germinates by develop- 
ing a short tube (promycelium) on 
which four sporidia are borne. These 
sporidia are discharged in thousands, 
carried by the wind, and some of 
them infect the quince or the related 
plants already listed. The sporidia 
never reinfect the cedars. On the 
quince, the sporidia germinate, form- 
ing germtubes which grow into the 
tissues of the fruit and twig, causing 
the distortions and malformations 
already described. Finally the tubu- 
lar projections, which in mass are 
an orange fringe-like growth, develop 
another sort of spores, — ecio-spores. 
These are peculiar, like the sporidia 
developed on the cedar, in that they cannot reinfect the 
quince, but may infect the cedars. About one year is re- 
quired for the completion of the life-history of this pathogene. 
