P R E E A C E. 



When, some years since, I undertook to prepare for the Ray Society an outline view of 

 the structure, physiology, and systematic arrangement of the Foraminifera generally, I had no 

 idea of contributing anything else than an introduction to my friend Prof. W. C. Williamson's 

 ' Recent Foraminifera of Great Britain.' With the progress of my own researches, however, 

 I came more and more strongly to feel how unsatisfactory are the results of the method 

 pursued by M. D'Orbigny and by those who have followed his lead, both as regards the 

 multiplication of species, the distinction of genera, and the grouping of these genera into 

 families and orders. I found, moreover, that notwithstanding the dissimilarity between the 

 lines of inquiry pursued by myself on the one hand and by my friends Messrs. Parker and 

 Rupert Jones on the other, they led to conclusions most singularly accordant. My own studies 

 had been restricted to a hmited range of types (for the most part collected by Mr. Jukes on 

 the Australian coast and by Mr. Cuming in the Philippine Seas), which included, however, all 

 the most complex and highly developed forms of recent Foraminifera ; and I had specially de- 

 voted myself to the elucidation of their structure and physiology, and to the careful comparison 

 of their numerous varietal forms. Theirs, on the other hand, had involved the comparison of 

 the zoological characters of vast numbers of representatives of nearly all the generic types 

 of the group, fossil as well as recent, brought together from various parts of the 

 world, from various depths in the ocean, and from various geological formations ; but had 

 not been prosecuted with the same minuteness in regard to the details of internal struc- 

 ture or to physiological -relations. Yet we had all been alike brought to recognise— 



