3530 



THE LOWEST ANIMALS 



nothing remarkable about the tiny oval mass resembling the egg of a zoophyte* 

 but presently from the opening at one -end of the membranous sac or shell granular 

 threads of sarcode creep out and become fixed on the glass slide; slender trunks of 

 sarcode extend themselves, and divide into finer and finer branches, which reunite 

 to form a network of streaming granular filaments ever changing in form, and 

 which may extend to six or eight times the length of the body. Every fibre 

 exhibits an up and down stream of granules suspended in clear hyaline sarcode. 

 A diatom, infusorian, or other edible prey, coming in contact with the pseudopods, 

 is covered with a mass of protoplasm formed by fusion of several filaments, drawn 

 down to the mouth of the shell and engulfed. Gromia moves by means of its 

 pseudopods, which fix themselves and draw the body along. When alarmed, the 

 animal withdraws into its membranous test. 



a. Hyperamimina ; b. and c. Astrorhtza limicola ; b. Entire ; c. Cut open. 



The sandy Koraminifera, which are mostly deep-sea types, are composed of 

 masses of sarcode, sometimes of considerable size, which form shells or cases of 

 agglutinated mud, sand particles, or sponge spicules. They frequently attain a 

 large size; for instance, Bathysiphon, from the Atlantic and also from fourteen 

 hundred and twenty-five fathoms off Amboyna, forms a slender annulated tube, two 

 inches in length, and open at each end, the walls of the tube being composed of 

 cemented sponge spicules. Haliphysema is found in shallow water in the North 

 Atlantic in the form of minute club-shaped bodies, one-twentieth of an inch in 

 height, with the narrowed lower end attached by a disc to zoophytes, etc., and with 

 the surface bristling with sponge spicules. Hyperammina, generally distributed in 

 from sixty to three thousand fathoms, makes a test of cemented sand grains and 

 sponge spicules, at first forming a globular chamber with a long branched neck, the 

 branches of which again branch. Astrorhiza forms stellate single-chambered shells 



