SIMPLE TYPE OF ORBITOLITES. 495 



budded-off three Stolons, which swell into new Rub-segments from 

 which the first King is formed. Scarcely any two specimens are 

 precisely alike as to the mode in which the first Ring originates 

 from the Circumambient Segment ; 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 

 afterwards followed, is probably the typical arrangement) ; whilst 

 in other cases (as in the example before us) the number of these 

 primary offsets is extremely 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 

 disk ; 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. 



378. Although no opportunity has yet been obtained for a 

 microscopic examination of these animals in their living state, yet 

 there can be no reasonable doubt that the Radial extensions of the 

 outermost zone issue-forth as Pseudopodia from the marginal pores, 

 and that they search-for and draw-in alimentary materials in the 

 same manner as do those of other Foraminifera ; the whole of the 

 soft body, which has no communication whatever with the exterior, 

 save through these marginal pores, being nourished by the trans- 

 mission of the products of digestion from zone to zone, through 

 similar bands of protoplasmic substance. In all cases in which 

 the growth of the Disk takes-place with normal regularity, it is 

 probable that a complete circular zone is added at once. When 

 the Sarcode-body has increased beyond the capacity of its enve- 

 loping disk, it may be presumed that its Pseudopodial extensions, 

 proceeding from the marginal pores, coalesce, so as to form a com- 

 plete annulus of Sarcode round the margin of the outermost zone ; 

 and it is probable that it is by a deposit of Calcareous matter in 

 the surface-portion of this annulus, that the new Zone of Shell-sub- 

 stance is formed, which constitutes the walls of the cells and pas- 

 sages occupied by the soft Sarcode-body. Thus we find this simple 

 type of organization giving origin to fabrics of by no means micro- 

 scopic dimensions, in which, howevei", there is no other differen- 

 tiation of parts than that concerned in the formation of the Shell ; 

 every segment and every stolon (with the exception of the two 

 forming the ' Nucleus ') being, so far as can be ascertained, a pre- 

 cise repetition of every other, and the segments of the Nucleus 

 differing from the rest in nothing else than their form. The 

 equality of the endowments of the Segments is shown by the fact, 

 of which accident has repeatedly furnished proof, — that a small 

 portion of a Disk, entirely separated from the remainder, will not 

 only continue to live, but will so increase as to form a new disk ; 

 the want of the Nucleus not appearing to be of the slightest con- 

 sequence, from the time that active life is established in the outer 



