Boyal Microscopical Societij. 167 



that the joints cannot be seen when magnified 1000 diameters. 

 The joints in the other filament can be observed when magnified 

 about 400 diameters. Both descriptions of filaments are found in 

 water containing sewage, but in some diluted samples of effiuent 

 sewage water I have only been able to discover the finer filaments, 

 while in others only the larger. In mixtures of urine or of a 

 minute quantity of alkaline phosphate with New Eiver water, the 

 larger filaments are found, and they occur in the network form. 



Both filaments soon break into pieces of various lengths and 

 difi'use themselves throughout the liquid. In the case of the 

 filament produced in the water containing urine, I observed that 

 in its earlier stages of development the filament appeared to be 

 surrounded by a sort of soft casing, which gradually separated 

 from the filament, the jointed character of which was then readily 

 distinguishable. 



While dealing with the subject, it is proper to point out that 

 when some descriptions of ditch and other dirty water are submitted 

 to the test, filaments similar in character are developed, and after 

 these break uj) and become difiused throughout the liquid, they 

 are hardly distinguishable from those produced in water containing 

 sewage ; in fact the only difference apparently observable is that the 

 broken filaments are much less numerous than in samples of efiluent 

 sewage waters, which undoubtedly produce the filamentous growths 

 in great abundance. The dirty waters upon which I operated 

 became turbid, and were found to contain bacterian bodies. 



The rapid growth of the filaments in the presence of phosphate 

 of lime and cane-sugar is very curious and interesting, and the 

 interest in their development is somewhat heightened by the fact 

 that the filaments . will, I think, be found to belong to a higher 

 order of vegetation than fungi, viz. to the Algae and probably to 

 the class Oscillatoriaceae. 



In samples of water containing sewage a large proportion of 

 the bacterian-like bodies partake more of the character of vibrios 

 than the corresponding organisms in water containing phosphate of 

 lime, and free from organic matter ; but the line of distinction is so 

 fine that I could not undertake at present to define the diflerence. 

 Those bacterian bodies which are produced in water containing a 

 large proportion of sewage, and especially urinary sewage, appear 

 to be more flexible than those developed in the presence of sugar 

 in efiluent sewage water, or in water containing phosphate of lime 

 only. The most active condition in which they are found, is when 

 they consist apparently of two cells or divisions, and in this form 

 they are extremely rapid in their motions, and are seen darting 

 constantly across the field, and occasionally stopping and performing 

 a revolving motion. I cannot help thinking that these bodies, 

 which multiply with such extreme rapidity and produce such rapid 



