270 
from the banks which have been of so fre- 
quent occurrence. * * * The little pel- 
lets, which were spoken of as seen after the 
slide, were rolled up by the avalanche as it 
passed over the solid ground beneath. 
Mr. Bourne undoubtedly recognized 
the phenomenon as one of the land- 
slides of common occurrence with 
accompanying clouds of dust in any 
area where outcropping strata, espe- 
cially moistened clay beds, slip to lower 
levels by weathering and gravity. His 
explanation of the origin of the little 
pellets, claystones or concretions as 
now generally designated, was not 
such a happy one. 
From time to time there were other 
references, particularly to the Connec- 
ticut Valley concretions, wherein quite 
different views were expressed as to 
their origin. Many people honestly 
believed they were fossil animals of 
prehistoric time and called them clay 
dogs. The regularity of the discoidal 
forms seemed to prove that they had 
been turned out on a lathe and had 
been used for money. A few persons 
surmised that running water had worn 
them into their present shapes. Still 
others thought they were sports of 
nature or were of supernatural origin. 
The doll-like forms found in clay banks 
of the South were explained thus by 
the old colored mammies: ‘‘When the 
good Lord formed these little children 
out of clay He forgot to breathe the 
spirit of life into some of them.” 
In time, chemical analyses gave a 
clue to the source of these curiosities. 
The hard claystones revealed 40 to 50 
percent calcium carbonate in their 
composition, while the soft clay layers 
in which they were embedded showed 
only 2 to 3 percent. It seemed there- 
fore probable that the original clay 
beds had been robbed of their car- 
bonate content by circulating ground 
waters which in turn had deposited 
this lime around centers of attraction, 
thereby building up the claystones. 
Accordingly, they must have been 
formed after the deposition of their 
containing beds; in other words, they 
were of secondary origin. Various 
ANNUAL REPORT SMITHSONIAN INSTITUTION, 1948 
other types of concretions indicate 
their formation at the same time as the 
enclosing beds, wherefore they are 
classified as primary in origin and 
must be explained differently. 
Collecting concretions as a hobby 
has been a lifelong pleasure of many 
persons occupied otherwise in quite 
different pursuits. Among the several 
publications on New England concre- 
tions, was a little-known memoir 
“Concretions from the Champlain 
Clays of the Connecticut River Val- 
ley,” published privately by Mrs. 
Jennie M. Arms Sheldon in Boston, 
1900. Mrs. Sheldon’s work was based 
upon a series of 1,400 specimens, but 
the present writer had the advan- 
tage of studying a collection of more 
than 3,000 selected examples, the gen- 
erous gift of the late H. N. Pringle 
of Washington, D. C., to the United 
States National Museum. Mr. Pringle, 
while occupied professionally in Wash- 
ington, spent many summer vacations 
near Ryegate, Vt., on the Connecticut 
River, a locality long noted for its 
abundant well-preserved concretions. 
Here, as shown on plate 1, they are 
found in outcrops of the thin-bedded 
glacial clays exposed on Clay Island, 
a mound about 75 feet high nearly 
encircled by the Connecticut River 
and Sly Brook. Choice specimens 
from Mr. Pringle’s collection illus- 
trating the origin and _ progressive 
growth of these objects now adorn an 
exhibition case in the Museum’s hall of 
physical geology (pl. 12), while the 
examples figured on the other accom- 
panying plates are preserved as type 
specimens with many others in the 
study series of the department of 
geology. From the types figured it 
would appear that all the Ryegate 
specimens were exceptionally perfect. 
This, however, is not true, because 
these types are only examples selected 
from thousands of bullet and pebble- 
shaped, spherical, flattened, and all 
sorts of irregular forms which had not 
attained complete development. 
To understand the formation and 
