— '58 —

the post-mortem destruction of bone by beetles. Some ulcerated crania
which, we have found present a picture of bony diseases that might
possibly result from the action of the syphilitic virus (PI. LIII), but as
none of the cardinal signs of syphilis in the teeth, or in any of the limb
bones, have been met with, it is best to seek some other explanation for
them.

Simple periostitis of the cranium is a condition that may be extremely
diffuse, and at times, from the amount of vascularization of bone
present, has evidently been severe. The simple periostitis is caused
possibly by the extremely common habit of carrying weights upon
the head ; and simple ulceration of the cranium is not an uncommon
condition to-day. These simple cranial ulcers are probably merely
an extension of the process that produces the periostitis, and in the
ancient skulls the ulceration leaves well-marked traces upon the
cranial bones.

There is frequently great destruction of the outer table of the cranial
wall, and in many cases portions of the skull and scalp have evidently
sloughed away. These lesions present an appearance that could easily
be accounted for by supposing syphilis to be the pathological process
involved ; but in the entire absence of any other manifestation of the
disease amongst these people, it is best to regard them as non-syphilitic
in origin.

The disease which shows itself with by far the greatest frequency in
the bodies of all periods is " rheumatoid arthritis." It appears under
a multitude of guises; and in the description of the cases which we have
found the nomenclature adopted by Ziegler will be used throughout.
This disease is of universal distribution in all the cemeteries that we
have so far examined, but it is more common among the archaic peoples
than among those buried in more recent historical times. The most
common manifestation of the process is spondylitis deformans, and its
site of election is in the lower lumbar region : so very common is this
disease that in the prehistoric cemetery in the main street of Shellal
no adult body failed to show some traces of its presence. The disease
presents very varied pictures, all of which are merely grades in its
severity; it may be present as a mere lipping of the adjacent edges of
individual vertebrae, or it may involve many separate vertebrae, and
even ankylose whole series firmly together. It is very common to find
in the prehistoric bodies two or more lumbar vertebra1 fused by irregular