1915] on Beauty, Design and Purpose in the Foraminifera 479 



The other important function is the capture of food, which is 

 caught outside the shell and usually drawn into it, as in this case 

 (SI. 58) of Miliolina darramlii, which has ingested a smaller Forami- 

 nifer and a diatom. ^ 



It is a niDst significant, and at present unexplainable, fact that 

 these minute protoplasmic globules secrete such varied materials for 

 the formation of their shells from the surrounding medium, as car- 

 bonate of lime, silica, and even sulphate of strontium, but the nature 

 and character of their protoplasmic bodies which perform this function 

 defies analysis or definition in the present state of our knowledge. 



Their life-cjcles have been carefully studied by Lister,- Schau- 

 dinn,^ Winter,"^ and others, and the fact has been established that 

 most, if not all, Foraminifera exhibit the phenomenon called dimor- 

 phism (that is to say, they start with a large or a small central 

 chamber) (SI. 59 and SI. 60), and that the small chambered (or 

 microspheric) individuals reproduce themselves by means of amoebul^ 

 expelled from the shells producing the megalospheric young, whilst 

 the large chambered (SI. 61) (or megalospheric) individuals dis- 

 charge flagellispores which conjugate with the flagellispores of other 

 individuals and producing microspheric young, recommence or con- 

 tinue the life-cycle. 



Within the last few months, owing to the initiative and manipu- 

 lative skill of Mr. J. E. Barnard, a new and very striking method of 

 investigation has been instituted which not only reveals the internal 

 structure of Foraminifera without the need of cutting sections, and 

 so destroying the specimens, but may have far-reaching results when 

 applied to the study of the living protoplasmic bodies. This is the 

 apphcation of the X-rays to the shells, the results of which operation 

 are highly interesting and significant.-^ Here is a very thick and 

 opaque species, B'doculina hidloides (SI. 62). The application of the 

 X-rays (SI. 63) reveals the internal arrangement of the chambers 

 clearly. Here again is the coarse tropical calcareous form Opercidiiia 

 complanata (SI. 64), the whole of the interior septation of which 

 (SI. 65) is perfectly shown by the skiagraph. The process is espe- 

 cially valuable in connection with the arenaceous forms. Here 

 (SI. 66) is one of the most rugose species, and one w^hich is exceed- 

 ingly difficult to sectionize, owing to the sand -grains imbedded in 



^ E. Heron-Allen, Contributions towards the Study of the Bionomics of 

 the Foraminifera, Phil. Trans. Roy. Soc. (Lond.) 1915. {In the Press.) 



• J. J. Lister, Contributions to the Life-History of the Foraminifera, Phil. 

 Trans. Roy. Soc. (Lond.), vol. 186, B. pp. 401-453. 1895. 



^ F. Schaudinn, Die Fortpflanzung der Foraminiferen, Wiegmann's Archiv. 

 fiir Naturgeschichte, Jahrg. xlix. pp. 123-151. 



•• F. Winter, ZurKenntniss der Thalamophoren, Archiv. f iir Protistenkunde, 

 vol. vii. 1907. 



* J. E. Barnard, X-rays in Relation to Microscopv, Journ. R. Micr. Soc. 

 p. 1. London, 1915. 



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