STRUCTURE OF HALIPHYSEMA TUMANOWICZII. 483 



protoplasm, which, when teazed and examined in small 

 pieces, has the appearance of being built up by a meshvvork 

 of fine fibiillse; or, to put it in another way, appears to con- 

 sist of denser substance, honeycombed by very small 

 ''vacuoles" or spaces of less dense substance. Here and 

 there are denser granules and small corpuscles, smaller and 

 less emarginated than the vesicular nuclei. 



In no part of the body substance is there evidence of any 

 axial cavity comparable to the enteron of higher animals, 

 nor the slightest trace of a breaking up of the protoplasm 

 into areas or units corresponding to cells, with the exception 

 of the egg-like bodies of the anterior region. 



The external jyi'otoplasm. — In the specimens preserved in 

 chromic acid, though no expanded networks of protoplasm, 

 such as that seen by Mr. Kent in living examples, can be 

 observed, having as a matter of course been retracted and 

 shrunk during the disturbance preliminary to the action of 

 the preserving fluid, yet in all my specimens knob-like 

 masses of the protoplasm could be observed here and there 

 on the surface of the unbroken tubes. The prettiest 

 examples are those in which the protoplasm has been killed 

 and preserved whilst crawling along the surface of one of 

 the projecting spicules of the tube. In fig. 1 such knobs of 

 protoplasm are seen, and in fig. 3 a camera lucida drawing 

 is given of a spicule projecting well forward from the test of 

 a Haliphysema, having on its surface a quantity of stream- 

 ing (or rather what was streaming) protoplasm. An impor- 

 tant fact is exhibited by this specimen, namely, that the 

 vesicular nuclei pass out of the test and stream with the 

 protoplasm over the surface of the spicules, and probably on 

 to the network which is formed beyond in the living condi- 

 tion. One of the vesicular nuclei is seen in fig. 3 7i. 



From the preceding account it appears that the structure 

 of Haliphysema is not quite so simple as that which has 

 been supposed to characterise the body-substance of the 

 Lituolida. It seems to me very possible that we shall even- 

 tually find among the larger members of the varied groups of 

 organisms classed as " Foraminifera '^ as high a structural 

 differentiation as that exhibited by any of the naked fresh- 

 water forms of Gymnomyxa (Rhizopoda) such as Pelomyxa, 

 Chlamydomyxa, and Actinosphaerium. Possibly, when means 

 are taken to overcome the difficulties of observation pre- 

 sented by their opaque and resisting shells, the larger 

 " Foraminifera " may prove not only to be nucleated but to 

 be as highly organised (though not in the same way) as the 

 Radiolaria. 



