2 HISTORICAL SUMMARY. 



furnished them, but are derived from their bearing on the highest and most recondite 

 problems of Ph)'siology and of the Pliilosoph}" of Classification. 



The history of our knowledge of Foramimfera* may be divided into four periods. 



The first inchides all the observations made and published in regard to them, from the 

 time when they first attracted attention, down to the date when they were grouped together 

 by D'Orbigny as constituting a distinct type of structure. Among the earlier authors in 

 whose works notices of them are to be found, it may be well specially to mention Plancus 

 (lxxxiii), Gualtieri (li), Ledermuller (lxi), Spengler (cii), Gronovius (l), and Schroter 

 (xcv, xcvi) ; as it was on the figures and descriptions of the first three that Linnaeus founded 

 the accounts of the fifteen species which he admitted into the twelfth editionf of his ' Systeraa 

 Naturae' (lxiii), and on those of the last three that Gmelin based the seven additional species 

 which he added in the edition of the same work (xLViii) published by him in 1788. Nearly 

 all tliese species, whether straight, curved, or spiral, were ranged under the genus Nautilus ; 

 one only {Miliola scminulum) of those enumerated by Linnaeus, and another (Z?7Ko/ff nauiiloides) 

 of those added by Gmelin, having been referred by them to the genus So-pula. It is worthy 

 of notice that the tendency to variation so strikingly exhibited by the shells of this group w-as 

 clearly perceived by Linna?us ; who, instead of erecting every well-marked variety into a 

 separate species (as certain of his followers have done), endeavoured to fi.x upon the most 

 characteristic variety, and invested it with the appropriate specific name, differentiating 

 other varieties by some mark, number, or subordinate designation. The descriptions given 

 by Linnaeus and Gmelin, though sufficient to distinguish the few types to which they apply, 

 either from each other or from the polythalamous Tcstacea with which they were associated, 

 would not now serve to distinguish them from the numerous allied forms which have since 

 become known ; but b\" an examination of the original figures and descriptions given by the 

 authors from whom those systcmatists derived their information, Messrs. Parker and Rupert 

 Jones (lxxvi) have succeeded in identifying each of the forms to which they gave specific 

 designations, and have indicated their characters in accordance with the present state of our 

 knowledge of the group. 



The next important contribution to our knowledge of Foraminifera was made by Messrs. 

 Boys and Walker, in their work (ix) on the minute shells found in the sand in Sandwich Bay and 

 its neighbourhood, the descriptions being by Jacob, and the drawings by Walker, from 

 specimens collected by Boys. An account of this work having been already given in Prof. 

 Williamson's monograph (ex, Introduction, pp. vi), it will be sufficient here to remark that 

 (as Messrs. Parker and Rupert Jones have pointed out), amongst the Foraminifera which they 



* I have thought it advisahle to limit my historical summary to the most important among the 

 many coutribntions to our existing knowledge of the group. A far more minute history, iu regard 

 to NumtnuHtes and their allies, is given hy MM. D'Archiac and Haime in their ' Monographie des 

 Nummulites' (i). And iu Professor Williamson's 'Recent Foraminifera of Great Britain' (to which 

 valuable Monograph an excellent Bibliography is appended) special notice is taken of all who have 

 contributed to our knowledge of this department of the British Fauna. 



t " Previous editions," says Professor Williamson, " contained the Polythalamia (' Nautili ') 

 enumerated by other writers; but in the ninth, Linnscus separates them into species, in the tenth he 

 gives them specific names, and in the twelfth he attaches to them the synonyms of other authors." 



