147 
Saprogenesis. With the formation of the teliospores, the host 
has succumbed. The rusted twigs and needles fall to the ground while 
the old stalks stand erect during the winter or fall under the weight of snow. 
On these stalks, twigs and needles, the pathogene in the form of dormant 
teliospores passes the winter. Under the conditions of moisture and 
temperature that start the host into growth in the spring, the teliospores 
on the old host-debris become active. They germinate in situ forming 
a promvcelium from each cell of the spore. Four basidiospores are pro- 
duced on each basidium. Each is uninucleate, its nucleus having been 
derived through the reduction division of the fusion nucleus of the telio- 
spore. These sporidia, as we have seen, constitute the primary inoculum 
which infects the young asparagus shoots and produces the aecia. 
REPORT 
1. Prepare a DIAGRAM showing the spore-forms, and the activi- 
ties of P. Asparagi DC. in proper sequence through the primary and 
secondary cycles. ; 
2. Give in some detail three fundamentally different methods of 
controlling the rust of asparagus, arranging them in order of practicability 
and efficiency. Justify by explanation and argument, the position to which 
each method is assigned in the sequence. 
