G. GENERAL NATURAL HISTORY AND ZOOLOGY. 231 



to a living mud. By direct light, on the other hand, they 

 appear as grayish-white, yellowish, or brownish bodies. Their 

 movements consist in an amoeboid and often lively creeping, 

 by means of processes which are usually broad and lobate, 

 during which the transparent body-substance often protrudes 

 at the margins in elevations and undulations. This funda- 

 mental substance of the body consists of a hyaline protoplasm 

 of irregularly frothy or vesicular consistency, containing, be- 

 sides the above-mentioned ingested particles, a great number 

 of very peculiar elementary particles. Among these there 

 may be distinguished round or roundish oval nucleiform bod- 

 ies and fine bacilliform structures. Of the former by far the 

 greater number consist of shining pale bodies without any 

 special structural characters, but of great firmness, and pre- 

 senting considerable resistance to reagents (acetic acid and 

 caustic potash). These bodies may possibly be correlated 

 with the coccoliths, etc., of Bathybius. Besides these, how- 

 ever, there are less numerous roundish nuclei of softer con- 

 sistency, and with more or less finely granular contents, 

 which, from their whole nature, must undoubtedly be regard- 

 ed as equivalent to the ordinary cell-nuclei. 



Hence, in spite of its great simplicity in other respects, Pe- 

 lobius represents a pluricellular organism, and is not to be 

 referred to the so-called monera, like Bathybius haeckelii, ac- 

 cording to the investigations of Huxley and Haeckel. Nev- 

 ertheless, in connection with its possible relationship to Ba- 

 thybius, it must be noticed that the cell-nuclei of Pelobius 

 may occur in very variable quantity, often in so small a num- 

 ber as almost to disappear altogether; and farther, that they 

 can be detected only in the perfectly fresh state. This latter 

 statement applies also to the frothy vesicular arrangement 

 of the body-substance, which disappears immediately after 

 death or the application of reagents. 



The second kind of the chief elementary parts of Pelobius 

 consists of fine, clear, shining bacilli, which are scattered 

 through the whole body, and likewise present great resist- 

 ance to the action of acetic acid and caustic potash. These 

 were mentioned by Dr. Green in a former publication, when 

 he expressed the opinion that they originate in certain nu- 

 clei, which, however, he has since seen reason to doubt. 



We are promised farther details in regard to this substance, 



