OKBITOLITES 



807 



The idea of the nature of the living occupant of these cavities 

 which might be suggested by the foregoing account of their arrange- 

 ment, is fully borne out by the results of the examination of 

 the sarcode-body, which may be obtained by the maceration in 

 dilute acid (so as to remove the shelly investment) of specimens of 

 Orbitolites that have been gathered fresh and preserved in spirit. 

 For this body is found to be composed (fig. 610) of a multitude of 

 segments of sarcode, presenting not the least trace of higher organi- 

 sation in any part, and connected together by ; stolons ' of the like 

 substance. The * primordial ' pear-shaped segment, a, is seen to 

 have budded off its ' circumambient ' segment, 6, by a narrow foot- 

 stalk or stolon ; and this circumambient segment, after passing almost 

 entirely round the primordial, has budded off three stolons, which 

 swell into new sub- 

 segments from which 

 the first ring is formed. 

 Scarcely any two speci- 

 mens are precisely alike 

 as to the mode in 

 which the first ring 

 originates from the 

 ' circumambient seg- 

 ment ; ' for sometimes 

 a score or more of 

 radial passages extend 

 themselves from every 

 part of the margin of 

 the latter (and this, as 

 corresponding with the 

 plan of growth after- 

 wards followed, is 

 probably the typical 

 arrangement) ; whilst FlG- eiO.-Composite animal of simple type of Orlito- 

 in other cases (as in lites complanata: a, central mass of sarcode; 

 the example before us) ^> c i rcumam bient segment, giving off peduncles, in 

 .v which originate the concentric zones of sub-segments 



the number ot these connected by annular bands. 



primary offsets is ex- 

 tremely small. Each zone is seen to consist of an assemblage of 

 ovate sub-segments, whose height (which could not be shown in 

 the figure) corresponds with the thickness of the disc ; these sub- 

 segments, which are all exactly similar and equal to one another, 

 are connected by annular stolons ; and each zone is connected with 

 that on its exterior by radial extensions of those stolons passing off 

 between the sub-segments. 



The radial extensions of the outermost zone issue forth as 

 pseudopodia from the marginal pores, searching for and drawing in 

 alimentary materials in the manner formerly described ; the whole 

 of the soft body, which has no communication whatever with 



is formed by three or four turns of a spiral closely resembling that of a Comuspira 

 with an interruption at every half-turn, as in Spiroloculina, the growth after- 

 wards becoming purely concentric. 



