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THE POPULAR SCIENCE MONTHLY 



like and reticulating pseudopodia with granular matter instead of a 

 nucleus, and with calcareous, membranous, or arenaceous skeletons ; 

 the Radiolaria and Lobosa, the first being the lowest, and embracing 

 Eozoon. The reticularis, may be still further divided into two sub- 

 orders, Perforata and Imperforata, the first having calcareous skele- 

 tons penetrated with pores. This is the higher one, and holds Eozoon. 

 Of the three families JNummulinidce, Globigerinidai,- and Lagundai, 

 Eozoon belongs to the first and the highest in rank. It is not strictly, 

 then, the lowest of the animal kingdom, though very near to it. 

 Fig. 1 shows several species of the foraminifera. 



Fig. 1. Rhizopods. 

 a, Orbulina universa; 6, Globigerina rubra; c, Chrysalidina gradata ; d, Cuneolina pavonia; 

 e, Grammostomiim phyllodes; /, Rotalia globosa ; g, Fiabellina rugosa ; h, Frondicularia 

 annularis ; i, Nummulitea nummularia. 



The animal part of the rhizopods is a gelatinous body called sar- 

 code, a bit of scarcely-organized protoplasm. Food is taken iu through 

 the outer wall, and is made into small pellets, which are surrounded 

 by a digestive fluid in extemporized stomachs. Minute granules move 

 about the interior, perhaps the substitute for a circulating fluid ; and 

 the outer wall can be moulded into the long processes called pseudo- 

 podia, used for locomotion and prehension. When these rhizopods 

 secrete stony matter for a covering, the interior is the same structure- 

 less mass ; but the shells assume characteristic forms for the different 

 varieties. The Orbulina consists of a single cell with one orifice, 

 but permeated by numerous microscopic pores, through which the 

 protoplasmic material can ooze and form the pseudopodia. In the 

 Globigerina and other genera there are several cells agglutinated 

 together, all communicating with one another. In many species the 

 thin cell-wall is inadequate for the wants of the structure, and an ad- 

 ditional growth or "supplementary skeleton " is added, traversed by 

 tubes larger, longer, and more branched, than in the first. In the 

 ocean these minute creatures swarm in astonishing numbers, and 

 their remains accumulate at the bottom, commingled with a paste 

 of still more minute coccoliths and calcareous debris to form the ooze 

 brought up in the sounding-lead from the telegraphed plateau. When 



