GR03IIA 



735 



generally, was first established by Dr. Wallich. The sarcode-body 

 of this animal is encased in an egg-shaped, brownish-yellow, chitinous 

 envelope, which may attain a diameter of from jVth to r \yth of an 

 inch, looking to the naked eye so like the egg of a zoophyte or the 

 seed of an aquatic plant, that its real nature would not be suspected 

 so long as it remained quiescent. The 'test' has a single round 

 orifice, from which, when 

 the animal is in a state 

 of activity, the sarcodic 

 substance streams forth, 

 speedily giving off ramify- 

 ing extensions, which, by 

 further ramification and 

 inosculation, form a net- 

 work like that of Lieber- 

 kuehnia. But the sarcode 

 also extends itself so as 

 to form a continuous 

 layer over the whole ex- 

 terior of the test." and 

 from any part of this 

 layer fresh pseudopodia 

 may be given off. By 

 the alternate extension 

 and contraction of these, 

 minute protophytes and 

 protozoa arc entrapped 

 and drawn into the in- 

 terior of the test, where 

 their nutritive material 

 is extracted and assimi- 

 lated ; and if the ' test 

 (as happens in some 

 species) be sufficiently 

 transparent, the indi- 

 gestible hard parts (such 

 as the siliceous valves of 

 diatoms, shown in fig 

 571) may be distinguished 

 in the midst of the sar- 

 codic substance. Bv the 



/ 



same agency the Gromia 



sometimes creeps up the sides of a glass vessel. In the intervals "of 



quiescence, on the other hand, the wiiole sarcodic body, except a 



film that serves for the attachment of the test, is withdrawn into its 



interior. 



Another example of the reticularian group is afforded by the 

 curious little Micnujromia socialis (fig. 572), first discovered by Mr. 

 Archer, and further investigated with great care by Hertwig, 1 which 



FIG. 571. Gromia oviformis, with its 

 pseudopodia extended. 



1 'Ueber 'Microyromia,' in Arcltiv fiir Mikr. Aunt. bd. x. Supplement. 



