38 
cations of Aveidium which looked lke dA Berberidis, found 
on the Barberry. This plant, he remarked, was of interest at 
the present time as De Bary has ascertained that the spores of 
the Wheat blight, Puccinia graminis do not germinate when 
sprinkled upon the leaves and stalks of the cereals, which 
this must infests, while they will germinate on the leaves of 
the Barberry, and there give rise to the Atcidium Berberidis. 
The spores of this again will not grow upon the Barberry but 
on the wheat produce Uredo and thereafter Puccinia. ‘This 
proves that these hitherto supposed distinct genera are but 
stages of one species. 
Prof. T. Egleston Jr. exhibited a fine suite of crystallized 
diamonds including about all of the known forms in which 
this gem is found. ‘They varied in color as well as form 
and many were curiously distorted as well as twins. The 
distortions of this mineral are very numerous and of great 
interest to the mineralogist, as well as dealer in gems. The 
cube is always opaque. Even if the crystaline form were not 
‘well marked, yet a diamond could be told from its peculiar 
cleavage, which was unmistakable. This cleavage was taken 
advantage of often in preparing gems for cutting, but some- 
times it could not be employed on account of the shape of 
the stone which would be injured in such cases. 
Prof A. M. Edwards read a 
Note on ITACOLUMNITE. 
To those accustomed to the use of the Microscope it is not 
a matter of surprise that persons who do not commonly 
employ that instrument in research should make very serious 
mistakes in interpreting what they think they see by means 
of it; the more especially when high powers of magnification 
are made use of. The delicacy of manipulation necessary to 
work with the microscope at all satisfactorally and the educa- 
tion of the eye required for the proper seeing by means of it 
are not generally understood, sothat those who are not skilled 
microscopists are extremely Hable to be led into error. 
Vou. I. 3 
