No. 33.] 371 
DisEAsEs OF THE QUINCE. — 
VYuince Blight. 
This has been treated under the subject of pear blight. It has all 
the characteristics of apple blight, and, like that, does not cause the 
dead parts to turn black, but only brown. I have never, however, 
seen the reddening of the hairs and tissues noticed in the apple. 
Treatment is the same as for pear blight. 
Lear BrRownness. 
Morthiera Mespili, F'ckl., var., Cydonia C. & FE. 
_ This disease of the leaves is very similar, if 
not identical, with that on pears. The spots 
made by the fungus are, however, more con- 
spicuous, being of a light-brown color, and show- 
ing equally well on both sides of the leaf. They 
are most often about an eighth of an inch across, 
nearly round, but coalescing in places into ex- 
tended brown patches. The central black dot is 
r; . very noticeable upon close scrutiny. This is a 
ig. I. — Mycelium : : 
and spores of Morthi. Common disease, but does not often prove very 
era Mespili, Fckl.,var., harmful. It affects crowded nursery stock par- 
Cydonie C. & E., or ticularly, but may occur on trees of any age and 
quince leaf brownness. ioeatt NGit duel eh ae ted 
Magnified 250 diame. location. No remedy has yet been suggested. 
ters. Original. 

Lear Mitprw. 
Podosphera tridactyla, ( Wall.) 
This, like most of the parasitic white mildews grows entirely upon 
the surface of the supporting plant. It consists of a cobwebby film 
of interlacing filaments, spreading over both surfaces of the leaf, 
but best developed on the upper side. To the naked eye it appears 
like a whitening or mouldiness of the surface ; almost every one has 
noticed the very similar affliction in lilacs. It usually appears in 
June, soon producing an abundance of colorless spores to spread the 
fungus rapidly to other leaves and other trees. In the latter part of 
July the minute dot-like fruits begin to appear, and continue to do 
so until the leaves fall. These look to the naked eye like mere par- 
ticles of dust, but their regularity in size, perfect roundness, and not 
being dislodged by blowing or slight friction will usually distinguish 
them. The resting spores, which are able to withstand the rigors 
of winter and reproduce the mildew in the spring, are contained in 
these fruit dots. 
The disease was noticed on the lower limbs of quince trees, grow- 
ing against a wall where they were somewhat shaded. The fruit- 
dots were produced in the greatest abundance. The fungus is one 
