10 PKOTOZOA. 



cells and passages occupied by the soft sarcode body. Thus we find this 

 simple type of organization giving origin to fabrics of by no means mi- 

 croscopic dimensions, in which, however, there is no other differentia- 

 tion 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 or centre) being, so far as can be ascertained, a precise repeti- 

 tion of every other, and the segments of the nucleus differing from the 

 rest in nothing but their form. The equality of the endowments of each 

 segment is shown by the fact (of which accident has frequently furnished 

 proof), that a small portion of a disk entirely separated from the re- 

 mainder will not only continue to live, but will so increase as to form a 

 new disk, the loss of the nucleus not appearing to be of the slightest 

 consequence from the time that active life is established in the outer 

 zones. 



(22.) In Faujasina and the Nummulites, apparently the most highly 

 organized of the Foraminifera, the shell is of more complicated struc- 

 ture, being permeated by a system of radiating interseptal canals com- 

 municating with the exterior. 



(23.) For the following observations relative to the reproduction of 

 the Foraminifera we are indebted to Professor Max Schulze *. 



Remarking that an individual of the genus Triloculina (D'Orbigny) 

 had become stationary for several days, and enveloped, as is not usual, 

 in a thin layer of brownish slime, Professor Max Schulze f paid par- 

 ticular attention to it. At the end of a few days after it had become 

 quiescent, minute spherical, sharply denned granules were detached 

 from the brownish slimy envelope, and in the course of a few hours the 

 animal was surrounded with about forty of these corpuscles, which 

 gradually became more and more separated from it. Microscopic exa- 

 mination proved that these were young Foraminifera. When viewed 

 by transmitted light, they presented a pale-yellowish-brown calcareous 

 shell, consisting of a central globular portion partly surrounded by a 

 closely- applied tubular part, and having no septum in the interior. In 

 a short time the young animals protruded their contractile processes 

 from the anterior opening of the shell and crawled about upon the glass. 

 The parts of the body contained within the shell could be examined with 

 great accuracy under the highest magnifying powers, and were seen to 

 consist of a transparent, very finely granular, colourless material, of 

 which the protruded filaments were an immediate continuation. From 

 the circumstances under which the young Foraminifers made their 

 appearance, they must necessarily quit their parent in a tolerably per- 

 fect condition. 



(24.) When the calcareous shell of the parent animal was carefully 



* Muller's Archiv, 185G, p. 163. 



t Professor Max Schulze, Ueber den Organismus der Polythalamien (Foramini- 

 feren). Leipzig, 1854. 



