RECENT MEMOIRS ON FRESHWATER RHIZOPODA. 331 



step in forming his genus Nebela as distinguished from 

 Difflugia, and I look forward with much interest to his forth- 

 coming work on these beings at large. 



Troglodytes zoster, Gabrieli (PI. XXI, figs. 1—7). 



Under the above name the author describes a form which 

 appears (as could seem obvious on comparison of the figures) 

 to belong to the same genus at least, if it be not indeed 

 specifically identical with Chlamtjdophrys stercorea, Cien- 

 kowski. This latter, as before mentioned, might seemingly 

 properly be referred to the genus Platoum, Eilh. Schulze. 

 The form now in question is found too in a similar kind of 

 habitat to Cienkowski's — in earth permeated by animal 

 excrement. If this conjecture be correct the name Troglodytes 

 would fall to the ground. 



But the author gives at considerable length his observa- 

 tions on the development of the form, which, although his 

 views may be found open to objection, are very interesting. 



He attributes to the " ctmjugation " a special significance 

 and importance as the primary or introductory generative act. 



Two forms meet by their frontal apertures (in the well- 

 known way), their pseudopodia become gradually drawn in, 

 and the outlying protoplasm becomes fused and form a 

 yellowish cylindrical mass between the two so conjoined in- 

 dividuals. From this latter there are given off" numerous 

 minute acute granuleless processes, forming a kind of super- 

 ficial piloe covering (fig. 1). In about half an hour and by 

 degrees the intermediate mass becomes smaller, the minute 

 processes disappear, a line of demarcation presents itself, 

 and the two animals become removed a little from one 

 another; the connecting sarcode parts, and the conjugative 

 act is over. They now appear, as it were, more lazy; their 

 movements less active, their pseudopodia less extended. On 

 the other hand, the dispersion of the median granular zone 

 internally goes on with shorter and shorter pauses, this state 

 lastly for probably several days. The hyaline homogeneous 

 body-substance, especially of the posterior zone, becomes 

 pale, the mass cloudy, and the demarcation of the zones 

 obliterated. The contractile vacuole becomes reduced in 

 activity and size. The nucleus and nucleolus, however, re- 

 main unaltered. The author, indeed, avers it does not at 



' B. Gabriel : " Untersuchungeri iiber Morphologic, Zeugung und Ent- 

 wickelung der Protozoen ;" i. : " Der Eatwickelungscyclus von Troyglodytes 

 zoster" in C. Gegenbaur's ' Morpiiologisches Jabrbuch/ Bd. i, p. 535, 



t. XX. 



