THE MUSEUM. 
15 
—a hematite and a chromite—which have afforded 
us plenty of food for thought and wonder, especially 
the rocks at the hematite mine. Associated with 
the iron ore is a great deal of chalcedony, and it 
is curious to note the great varieties of form, struc¬ 
ture and color assumed by the quartz rock. 
The agate is especially peculiar, forming often on 
the outside of the rock, like lace-work or tangled 
cords, and resembles flos-ferri or aragonite, for which 
I first mistook it. 
At present I am studying the mode of formation 
of the large boulders of hornblendic rock that one 
may see all along the Western Maryland Railroad. 
In regard to the origin of these rocks, scientists hold 
different views, one of the most popular being, I 
believe, that they are of glacial origin. Their true 
origin was pointed out to me by Dr. H. Lawrence, 
of Baltimore, and a patient study of them has con¬ 
vinced me that he is right. They are formed in the 
soil. If one digs in the ground where these boul¬ 
ders abound, he will find hard lumps of earth with 
nuclei of hornblende at the centre, in every stage of 
development, from the size of a pin’s head to that 
of an ostrich’s egg. They are formed precisely as 
all other concretions are, drawing their material 
around a centre from the surrounding earth, as illus¬ 
trated in the geode, and the boulders found in iron 
ore mines. 
Is it an ascertained fact that quartz has sometimes 
cleavage, or a tendency that way ? Mr. Dana men¬ 
tions its total lack of cleavage as one of its main 
characteristics. I have in my possession a piece of 
white quartz that I found on the shore of the Patux¬ 
ent River, near its mouth, which shows a strong 
tendency towards cleavage. It is an imperfect rhom¬ 
boid, and, when struck three times with a hammer, 
broke into planes parallel to each other and its 
smaller faces. It has at the centre, running length¬ 
wise through it, like the heart of a tree, another 
variety of quartz of a darker hue and a more com¬ 
pact texture. Will you be kind enough to put the 
query whether anything of the kind has been ob¬ 
served before ? 
Is it known that the excrescences, some of them 
as large as one’s fist, seen on the trunks and limbs of 
the gum and oak, are made and inhabited by a 
winged ant, not larger than the gnat? They burrow 
in the excrescence and line their snug little houses 
with a shelly substance not unlike that of the teredo 
or ship-worm. This is new to me, having only dis¬ 
covered it within the past week, but it may be old to 
your readers. Allen B. Quinan. 
April 20th, 1885. 
To the Editor of The Museum : 
Dear Sir :—This Chapter has been organized 
about five months. We have increased our mem¬ 
bership since our organization, and have also started 
a library. All the members are interested in the 
work. We hope to make a good collection this 
season, for which we are preparing a cabinet. We 
wish you success in the publication of The Museum, 
and hope it will be of benefit to the A. A. 
Yours truly, 
Willie H. Hugg, 
Sec’y Chap. 762, Balto., Md. 
CHAPTERS RECENTLY ORGANIZED. 
No. 810 (A.) 30 members, Sec’y, Mrs. E. M. Husted, 
Orchard Park, N. Y. 
No. 811 (A.) 7 members, Sec’y, G. S. Brownell, 
Nyack-on-Hudson, N. Y. 
No. 812 (C.) 24 members, Sec’y, Amos Spencer, 
Davenport, Iowa. 
No. 813 (A.) 5 members, Sec’y, Ridiard M. Gibson, 
Waupaca, Wis. 
No. 814 (A.) 4 members, Sec’y, Frank Hersey, 
Roxbury, Mass. 
No. 815 (M.) 4 members, Sec’y, H. S. Hadden, 
Brooklyn, N. Y. 
No. 816 (A.) 5 members, Sec’y, Rob’t L. Raymond, 
Cambridge, Mass. 
No. 817 (F.) 8 members, Sec’y, W. P. Cresson, Jr., 
Philadelphia, Pa. 
No. 818 (D.) 8 members, Sec’y, Pennington Sater- 
thwaite, Newark, N. J. 
No. 819 (A.) 10 members, Sec’y, Fred. A Menge, 
Hinsdale, Ill. 
No. 820 (G.) 4 members, Sec’y, T. H. Fay (Box 
60), Boston, Mass. 
Why do not some of the Chapters of the Agassiz 
Association, which are situated in favorable localities, 
take up the study of American archaeology as a 
specialty ? The subject is of the most engrossing 
interest. No other branch of science presents such 
a fruitful field for original research. 
