376 EXTRACTS AlfD AnSTRACTS. 



1)oilios, found with the two List, whoso orip;in is at prosont uncertain, 

 1ut which miiy bo derived, it is thouj^ht, iVom spares formed in the 

 i'ill-p,rown Begrjiatoa. With the snuill form Prof. Warniinf; compares 

 J/t>)ias gliscejis, Ehrbp;. ( Folvox ffJobuhis, 0, F. Miill.), which he thinks 

 may ])erhaps be the .cerm of another species of this penus. 



Monan Miillcri, "Warm. (Volvox pioictii7n, 0. F. Mull.),is sphcri<-al 

 or oval, rarely uniformly filled with sulphur-gi-ains, the latter being 

 usually collected toj^ether at one end, while the other end has a hya- 

 line appearance, and it is throui^h these two ends that the se])tum 

 passes in divi.sion. Motion is v(;ry rapid, but sometimes individuals 

 in the act of division move with prcat irrep^ularity ; cilia were not 

 seen, but sometimes small particles appeared to travel round the cells, 

 a fact which seems to indicate the presence of cilia. 



Like the last, but smaller than it, is 3Ionas fallax. Warm. ; the 

 border is often hyaline, and the outline irregular ; further, in the 

 resting state this species is scarcely distinguishable from an inorganic 

 crystal. 



A ribbon-like Schizophyte, with rarely more than 1^ spiral turn, 

 but much elongated (G-9 times longer than broad), is termed Sp/'ro- 

 monas Cohnii. Its outer wall is thick, anil sometimes longitudinal 

 strioD are observed on it, which go oif at the end in the form of 

 slender prolongations ; division takes place very suddenly in this 

 species. 



SpirocJiMe gigantea, Warm., has a cylindric, truncate, grayish- 

 coloured, apparently eciliate body, finely granular plasma without 

 trace of sulphur- grains, and a varying number of spiral turns, which 

 may reach to 1 6. In one locality divided individuals were met with, 

 thus affording indications of articulation. Indeed, Prof. Warming 

 thinks it probable that all species of Spirillum and all elongated 

 Bacteria have invisible articulations. 



The " acicular phase" of Bacterium termo is distinguished by the 

 name B. fiisiforme, and a much finer needle-shaped phase is adverted 

 to, but not named. 



Prof Warming did not succeed in directly making out the cell- 

 membrane ; in the true Bacteria he has never seen the plasma shrink 

 from the cell-membrane by the action of reagents, neither has he 

 observed any internal molecular or granular movement. Sometimes, 

 however, vacuoles are formed round the periphery, and then the mem- 

 brane is shown very distinctly. 



The grains of the plasma are of two kinds : — 1 . Strongly refringent, 

 without a well-defined bounding circle ; these are merely compacted 

 masses of the plasma. 2. The ordinary sulphur-grains resemble oil- 

 drops, and are surrounded by a dark circle. 



With regard to classification, Lankester's views as to generic com- 

 bination are regarded -vith favour ; and it is thought that Ophido- 

 monas, Spirillum, and / ihrio must be at once united ; also that certain 

 forms, as Monas vinosa and M. Okenii, were better placed with true 

 Bacteria. 



The only form of multiplication observed was by division. More- 

 over, the **zooglea" state was never seen in salt-water infusions. 



