[% onthly Microscopical 
Journal, Sept. 1, 1870. 
164 PROGRESS OF MICROSCOPICAL SCIENCE. 
simple lamelle, hanging from the internal surface of the mouth; thus 
proving the correctness of Vogt’s observations from alcoholic speci- 
mens. At times the peduncle would become congested, and a deep 
rose blush was markedly distinct. The sexes were distinct. The 
writer believes the Brachiopods to be true articulates, having certain 
affinities with the crustacea, but properly belonging to the worms, 
coming nearest the tubicolous annelids. They may better be regarded 
as forming a comprehensive type, with general articulate features. 
Possibly they have affinities with the mollusks, through the homolo- 
gies pointed out by Allman as existing between the Polyzoa and 
Tunicates. It is interesting to remember that Lingula, though one of 
the earliest animals created, has yet remained essentially the same 
through all geological ages to the present time.—American Naturalist, 
Itacolumnite under the Microscope.—Professor A. M. Edwards 
read the following note on the subject at the New York Lyceum of 
Natural History, on the 23rd of May :—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 satisfactorily and the education of the eye 
required for the proper seeing by means of it are not generally 
understood, so that those who are not skilled microscopists are ex- 
tremely liable to be led into error. What I am inclined to consider 
a case of this kind has lately been brought to my attention, and I am 
persuaded to make a note of it the more for the purpose of correcting 
a grave error in investigation, and one which is, strange to say, 
readily demonstrated to be an error. In 1867,* Dr. C. Wetherill 
published a well-written and seemingly-exhaustive paper, setting 
forth some “Experiments on Itacolumnite, with the explanation 
of its flexibility and its relation to the formation of the diamond.” 
In attempting to elucidate the flexibility of this rock he has made 
use of the microscope, and, in fact, mainly draws his conclusions 
from the revelations which he supposes that instrument makes. 
Some specimens of Itacolumnite, varying in tint from almost pure 
white to a rusty red tint, and in texture from finely granular to 
coarse and distinctly laminated, having come into my hands, I 
have been enabled to examine into this point of structure and 
attendant flexibility, which I have done with some care. It is 
well known that Itacolumnite is the accompanient and often the 
matrix of the diamond, hence the interest which attaches to its 
peculiarities, as it would seem in some way to be connected with the 
occurrence or formation of that gem. Detecting dark-coloured grains 
in it, Dr. Wetherill considers them to be black diamonds, and doubt- 
less he is correct in his supposition, but with this portion of his 
paper I do not desire to deal at the present time. It is with regard 
to the structure of the sandstone whereby it becomes flexible to the 
remarkable degree so evident when thin slabs are examined. The 
* ¢ Amer. Jour. Science,’ vol. xliv. 
