62 SNOW MOULDS. 



is not effectually exerted, a deterioration of the 

 crop takes place. When it is found in later 

 stages of growth, and on the glumes and palese 

 of the chaff, it is more injurious than when it 

 merely appears in the earlier periods of growth. 

 This is the proper place for a few remarks on 

 certain other fungi, not so common as the red- 

 rust, or red-robin, which are occasionally found 

 on the leaves of the wheat plant. One of these 

 is the erysiphe graminisy almost universal on it 

 in 1845, but which did not seem to do much 

 harm, and upon which therefore there is no 

 need to enlarge. On the continent, there are 

 two species of moulds which are extremely 

 curious, and one of them is fearfully destruc- 

 tive. The former called chionyphe, from its 

 being developed during snow, was discovered in 

 Iceland, by Thieneman. Two other species 

 have since been seen in the neighbourhood of 

 Dresden, where they were abundant. This sin- 

 gular mould is found on the snow, when it just 

 melts before the sun, without any general thaw. 

 It consists of spreading shining fleecy patches, 

 and the reproductive portion of it is sometimes 

 red and sometimes green. As soon as the snow 

 melts, it appears on the young herb in a stratum 

 resembling a cobweb of great delicacy, which is 



