28 
PEBBLE-SWALLOWING ANIMALS. 
reasons, the Penguin thinks well to burden his belly with boulders. 
Sir James Ross notes that in the stomach of one of them he found ten 
pounds weight of quartz, granite, and trap. Well, the poor thing 
needs, no doubt at too frequently recurring times, something to impart 
a sense of fulness and stability to the stomach ; for that organ is not 
only of huge size in proportion to the build of the bird, but has in 
common with the Seals and Sharks, and the majority of Deep Sea 
People, a flood of digestive juices capable of dealing almost (as a sailor 
would say) with scupper nails ! ” 
It is a curious fact (which has occurred many times in scientific and 
other matters) that two or more observers, working at the same time 
on a certain subject, at a distance from, and entirely unknown to each 
other, should hare been investigating similar phenomena, and 
arrived at similar conclusions in explanation of the facts. This is 
commonly termed “ the long arm of coincidence,” and in this instance 
it certainly is a long arm, extending many thousands of miles ! While 
the writer was working out the problem of the pebbles in the Rhaetic 
Bone-Beds, certain North American geologists were engaged on the 
pebbles found with remains of Saurians in Kansas and South Dakota. 
The following extracts from their reports furnish important evidence 
on the subject : — 
Kansas State Board of Agriculture (1st biennial report, p. 62). 
Professor Mudge, writing on the fossil Plesiosaurs found, notes 
“ another interesting feature, showing an aid to digestion similar to 
that of many living reptiles and birds. This consists of well-worn 
siliceous pebbles, from a quarter to half-an-inch in diameter . 
They were the more curious as we never found such pebbles in the 
Chalk or Shales of the Niobrara,” (These pebbles are now in the 
Yale collection). 
Dr. Williston (Palaeontologist to the University of Chicago)^ writes : 
“ At Ellsworth, Kanas (Benton Limestone), were found Plesiosaur 
bones with a lot of siliceous stones, 125 pebbles, with several vertebrae 
and ribs. Some pebbles were still attached to the ribs by the original 
matrix, showing deposition was contemporaneous with that of the 
skeleton. The pebbles vary in weight from 1 gramme to 170 grammes. 
The smaller ones were worn into more or less perfect ellipsoids, but the 
larger ones are more irregular in shape, having suffered less abrasion. 
It seems probable that most of the pebbles had been obtained by the 
animal from the sea beaches bordering the Black Hills, but not a few 
of them, consisting of red quartzite, are quite identical with the 
quartzite boulders so often found in the drift of Eastern Kansas, which 
have come from the vicinity of .Sioux City, Iowa. 
The specimens show conclusive!}" that the pyloric orifice must have 
been well provided with a sphincter, and that no solid substances 
passed into the intestinal canal ; one need never expect to find 
plesiosaur coprolites containing undigested remains of bones or other 
solid material. 
^Field Columbian Museum, No. 73 Geological Series, Vol. ii., No. 1, Plate, xxix. 
