BY D. McALPINE. 
451 
parasitic fungi and the utility of such knowledge to the grower, 
I cannot do better than quote from a letter recently received from 
Mr. George Quinn, Inspector under " The Vine, Fruit and 
Vegetable Protection Act," South Australia. He writes (May 
28th, 1895) : — " The disease (Pvccinia pruni) has been very preva- 
lent in our orchards in all parts of the Colony in the season just 
closing, and I am somewhat in doubt as to how its spores exist 
over the winter, for in orchards where the peach or plum trees 
have been thoroughly sprayed with Bordeaux Mixture, with 
excellent results, as far as the 'curl leaf is concerned on the 
former, and I am perplexed as to where the spores find refuge 
until the autumn when the pustules begin to show on the foliage 
of the trees. Do you think it possible for the spores which have 
fallen either before or with the diseased leaves to be ploughed 
into the soil and then be turned up again with the summer 
cultivator to rise with the dust among the foliage, and, the condi- 
tions being suitable, germinate 1 Do you think the spores of the 
various parasitic fungi which injure our fruits would lose their 
vitality completely if ploughed beneath the soil for a winter 1 
Would they not keep, like the seeds of some more highly organized 
vegetables, for a considerable time V 
To answer the above question, I am testing during the forth- 
coming season, 1st, if the uredospores retain their vitality and 
germinating power during the winter, both when lying on the 
surface of the ground and when buried to a depth of four or five 
inches; 2nd, at what time teleutospores are capable of germination 
and how they are affected by being buried in the ground four or 
five inches deep; and 3rd, if they can produce the disease in an 
otherwise healthy tree. The answer to these questions will fill 
up gaps in our knowledge concerning the life-history of this 
parasite and enable us the more effectually to cope with it. 
That the peach leaf rust of Australia is not due to a Uromyces 
should now be conclusively proved, because of the two-celled 
teleutospores and the uredospores having a transverse band of 
germ-pores instead of a single apical germ-pore. 
D D 
