THE RHAETIC BONE BEDS 
221 
notiorij which is simply an evasion of the difficulty, and 
raises other questions, such as — (1) Where did this deposit 
drift from ? and (2) How^ did the bed from which this 
imaginary drift took place originate ? It does not take 
long to see that this theory explains nothing, and is only 
an easy way of shelving the question. 
Now, it does not seem to have occurred to the advo- 
cates of the drift theory that there might be another and 
much simpler way of accounting for these pebbles, and 
yet such a process can be shown to be in operation at the 
present time. It is a fact, well known to all who have to 
deal with marine fishes, that their stomachs frequently 
contain an appreciable quantity of foreign material, in 
which pebbles figure largely. Whether these pebbles are 
swallowed accidentally or intentionally is debatable, but 
there is no doubt as to their presence, testimony being 
forthcoming from fishermen, yachtsmen, naturalists, and 
scientists on this point. In addition, we have evidence of 
the formation now proceeding of a fossiliferous deposit in 
the Torres Straits, in which pebbles derived from fish 
form a perceptible feature. It is further stated that 
reptiles (crocodiles, etc.) are also addicted to this habit, 
several notes to that effect appearing in various papers, 
both English and foreign. (See notes at end.) 
Need we go further for the explanation of the presence 
of these pebbles ? Here is a simple and natural solution, 
which has the additional advantage of fitting in with two 
otherwise awkward facts — (1) that these pebbles are always 
found in the Bone Beds ; and (2) that the most delicate 
and fragile fossils are uninjured by them, although found 
in actual contact ! 
As regard the number of these pebbles, it must be noted 
that quartz, being comparatively imperishable, would 
remain after a large amount of the animal debris had been 
removed or broken up by decomposition and other causes ; 
