CONTRIBUTION TO THE NATURAL HISTORY OF THE 



PEARLY NAUTILUS. 



By ARTHUR WILLEY, D.Sc. Lond., Hon. M.A. Cantab. 

 Director of the Colombo Museum, Ceylon. 



1. PERSONAL NARRATIVE. 



With 18 Text-figures. 

 LONGUM PER MARE, SED FAVENTIS UN DAE. 



As I have already explained in the prefatory note which accompanied the first 

 Part of these Zoological Results, my journey to the Eastern Archipelago was promoted 

 by the Managers of the Balfour Studentship in the University of Cambridge, with the 

 avowed object of procuring material for the study of the embryonic development of the 

 pearly Nautilus. It is well known that this moUuscan type occupies a comparatively 

 isolated position in the series of existing animal forms, and that it is a surviving relic 

 of an order which was dominant in former geological epochs. It is in fact one of the 

 best examples of what have been called persistent types or, by way of paradox, living 

 fossils, that is to say, relict types of pre-tertiary creation. 



It has been an object of serious investigation on the part of many of the foremost 

 zoologists of England, France, Germany and Holland during the nineteenth century, and 

 it was even one of Cuvier's regrets that he had never seen the inhabitant of the 

 chambered shell which had been, from time immemorial, an ornament of the conchologist's 

 cabinet. 



Of course the chance of "acquiring a complete set of developmental stages of such 

 a t\^e as this, from the moment of deposition of the eggs, through the period of 

 incubation, culminating finally in the hatching of the miniature organism, would be 

 enough to whet the enthusiasm and claim the devotion of any zoologist. The dis- 

 tinguished German naturalist, Dr Richard Semon, whose journey to Australia, " the land 

 of living fossils," has resulted not only in the publication of an imposing array of 

 technical monographs, but also in the composition of a delightfully instructive book, 

 spent some time at Ambo)Tia, and tells us that a principal aim of his stay on the 

 Moluccas was the study of Nautilus's development'. Elated by his successes in Australia, 

 Semon began to imagine himself "the happy possessor of a perfect series of developing 

 Nautilus pompilius." In this, however, he was disappointed, and it will be seen that 

 my efforts were only crowned by partial success, an eventuality for which I had 

 prepared my mind beforehand. 



1 Semon, E., In the Australian Bush, 1899, pp. 423 and 486. 



w. VI. 91 



