42 BOTANICAL GAZETTE [JANUARY 
The rapidity with Shick fungus spores are thus killed naturall 
such as Rhizopus and (Edocephalum, but is very slows acco’ fn 
plished i in forms like Aspergillus and Penicillium, whose coats pre 
sent great resistance to the entrance of poisons and the excre! 
of copper-dissolving compounds. As an example of such resis 
| ance to entrance, see experiments with Aspergillus in solutior 
_ of nickel sulfate,” in which 0.03 inhibited germination, PI 
: immersion in a normal solution (containing over 13 per ce 
NiSO,) for 48 hours at 28°C. failed to kill the spores. — 
_ Same form resists immersion in double normal ZnSO, ty 4 
Soa anhydrous ZnSO,) under similar conditions. : 
oye abe fost plant, too, is active in dissolving the Cu(OH) » 
| peach tree was: sprayed with Bordeaux mixture which cont 
a an excess of lime, as is ordinarily the case. Following this, 
_ tree was ‘sprayed several times during the day with e 
oe pure water to have an effect resembling dew. The following! 
S on water collected from the leaves, filtered and evaporated to 
io volume, showed just a slight copper reaction. Several : 
___ leafy branches were then removed and placed in a large beal 
: : : distilled y water, without i injury to any of the parts. After so2 
Mion some © hours these were removed and the solution , 
to small volume, | and tested for copper. Ag ma 
1S secured, indicating the presence of consi 
olution. The epidermis: of leaves, although pr ote 
, is well known to > be more or less permeable to 
: ‘ing in the cell sap, pe 
