112 FAMILY MILIOLIDA. 



he would, I tliink, be a mere speculator who should maintain the presence of a digestive 

 cavity in any of these parts, or the existence of an intestinal canal in the peduncular threads 

 which connect them together. The homogeneity of the component substance of the 

 "primitive mass," and of the entire assemblage of multiple segments, seems, indeed, to be 

 conclusively established by the following facts : — In all the spirit-specimens which I have 

 examined, the cavities of the outer zones are completely void, whilst those of the " primitive 

 disk" and of the inner zones are quite filled with their animal contents. This drawing 

 together of the soft body towards the centre is evidenced also in many of the larger specimens 

 which have been dried when collected in the living state, by the limitation of the red colour 

 that indicates tlie presence of the sarcode to the inner portion of the disk. In both cases it 

 may be presumed that the animal matter has shrunk together, in the former through the 

 corrugating action of the spirit, in the latter through desiccation. Now if the " polypidom" 

 of a Zoophyte or the " polyzoary" of a Polyzoon be similarly treated, there is no such 

 drawing together of the entire body, but each cell is found to contain the shrunk contents of 

 its own zooid ; and this difference seems to me to indicate a complete dissimilarity in the 

 characters of the two kinds of organisms. For it is obvious that the substance of the 

 peripheral segments of the Orbitolite-body can only be brought together towards the centre, 

 through being completely unattached to the walls of the cavities which it occupies, and 

 through having a form so alterable as to be capable of being drawn in threads through the 

 narrow connecting passages, and of then coalescing together again so perfectly that the masses 

 they form do not present the least trace of having been thus spun out. There is no known 

 kind of animal texture except sarcode that is susceptible of this kind of alteration ; and the 

 evidence of it which I have adduced seems to me extremely valuable, not only as establishing 

 the general nature of the animal body of Orbitolites, but also as fully justifying the assumption 

 that, in the living state, the sarcode is projected in pseudopodia through the marginal 

 apertures, and that alimentary particles are introduced by their instrumentality, as in other 

 Foraminifera.* 



163. Complex Type: External Characters. — From the simplest it will be convenient 

 to pass at once to the most complex type of structure presented by Orbitolites, the existence 

 of which is marked externally (as already noticed, ^ 155) by a multiplication of the ranges of 

 marginal pores. I have met with this form in specimens obtained by dredging from the 

 coast of Australia and from various parts of the Polynesian Archipelago, from the neighbour- 

 hood of the Philippine Islands, from the Red Sea, and from the J^gean ; and as the sands of 

 all these localities present the simpler type in great abundance, I am disposed to believe that 

 the former is really not the less widely diffused than the latter, and would be discovered 

 wherever it abounds, if properly searched for. The largest specimen in my possession, 

 measuring 7-lOths of an inch in diameter, is from the coast of Australia, where these 

 Orbitolites are so abundant at certain spots (as I learn from Mr. Jukes) that their entire 



* I tliiuk it desirable to repeat what I have already (xiii) stated upon this point, since the per- 

 sistence of Prof. Ehrenberg in his affirmation of the Bryozoic nature of these organisms might induce 

 those who rely on his authority to accept his figure of their animal (xxxis) as the representation of a 

 fact, instead of being merely the expression of tlieir author's idea. 



