PEARLS AND PEARL-OYSTERS. 201 
marrow-fat peas, as they lie in a newly-opened pod, is very suggestive. In order to 
preserve it from accident, and to facilitate its handling, this pearl cross has been 
mounted in a light open gold setting that in no way interferes with the full 
display of its unique character. It was under these conditions that it was laid upon 
a pearl shell corresponding in dimensions with that from which it was originally taken, 
and photographed as portrayed in the accompanying plate of its precise natural size. 
For the second photograph of this gem, reproduced on the preceding page, and represent- 
ing it in its original unmounted condition, the writer is indebted to Mr. Maitland Brown 
of Geraldton, Western Australia, one of the Members of the Syndicate to whom this 
celebrated Cross belongs. 
Much speculation has been indulged in respecting the probable nature of the 
foreign matter or nucleus, if any, that has formed the foundation of this remarkable 
pearl combination. It is suggested by Mr. Edwin Streeter, in his interesting treatise 
“ Pearling and Pearling Life”: London, 1886, that such a nucleus is possibly repre- 
sented by an adventitiously intruded fragment of serrated seaweed. There is, as a matter 
of fact, a species of seaweed, Hormosira Banksii, abundant in Australian waters, 
that takes the form of concatenations of spheroidal nodes which might be likened 
to strings of pearls. Pearl is, unfortunately, one of the substances impermeable to 
the recently discovered Rontgen rays; otherwise, the solution of this mystery of the 
“Southern Cross” might be easily achieved. Maybe, however, in the near future, a 
new X.X., X.X.X., or other occult luminant will be evolved which shall possess the 
property of laying bare and naked the nuclei of Pearls, the marrow within our bones, 
and even the quantity and quality of the packing of our brain-cases. The physician’s 
diagnosis of the eligibility or otherwise of candidates for Hanwell, or of paterfamilias’ 
determination of the most appropriate career for the training of his verdant olive- 
branches, will, under such conditions, be a lightsome task. 
As an illustration of the réle that adventitious substances may take in the 
fashioning of the form of pearl concretions, it may be mentioned that there is on view in 
the Conchological Gallery of the British, Natural History, Museum a Western Australian 
pearl shell into which a small fish, Fierasfer, which not unfrequently occurs as a 
commensal of the Pearl-oyster, having intruded, died, and, in lieu of ejectment, became 
imprisoned and completely enswathed in a nacreous cerement. Through the kind 
courtesy of the Director, Sir William Flower, the writer has been provided with 
facilities for taking a photograph of this remarkable specimen, which is reproduced 
overleaf. It sometimes happens that a little correspondingly commensal crab, 
cc 
