STRUCTURE OF GROMIA 101 



If the pseudopodia are killed more slowly, the connecting 

 thread which has been described between the varicosities 

 becomes destroyed or drawn in, and the pseudopodium 

 breaks up into a series of little spheres of protoplasm, which 

 often permit its original course to be plainly traced. A 

 similar breaking up into isolated spherules would, moreover, 

 only come about in a thread consisting of viscid fluid if it 

 were liquefied rapidly. It would then necessarily break up 

 into a great number of small droplets. 



Gromia Dujardini. M. Schultze, 1854 



I had numerous opportunities of observing 1 this very- 

 large and interesting Ehizopod in Naples. Together with 

 many other Ehizopods it was dredged on the coast of Capri, 

 from considerable depths. It kept alive for so long a time 

 that I was able to transport it to Heidelberg, and carry on 

 further studies there. 



Although the shell structure of this Gromia presents 

 many peculiar relations, I will not enter more fully into 

 the matter here, since I did not make a special study of it. 

 Only, in order to comprehend the figures, it must be noted 

 that the region of the mouth may take on a slightly different 

 appearance, according as whether the protoplasm is issuing 

 abundantly from the mouth-opening, or is retracted com- 

 pletely into the shell. In the former case the oral region 

 projects like a nipple, as is represented on Plate I. Fig. 2. 

 In the latter case, on the other hand, although the mouth 

 opening usually appears very much narrowed, or even nearly 

 closed, the nipple-like projection is quite shallow and flat- 

 tened off (Plate I. Fig. 1). The fairly thick shell wall appears 

 finely and radially striated in optical longitudinal section. At 

 the anterior pole it gradually becomes stronger, until at the 

 mouth opening itself it reaches a considerable thickness. 

 Up to a certain distance from the opening the shell retains 

 the radially striated appearance in section (Fig. 1, &). The 

 thickest part of the oral region has, on the other hand, 

 quite another structure. It appears finely granulated in 

 the section (Fig. 1, a), and is marked off by a sharp, 



