462 Transactions of the Society. 



XYI. — The Higher Bacteria {Sphserotilus). 

 By E. Moore Mumford. 



\{Read June 18, 1913.) 

 Plate XX. 



The botanist's definition of this organism is as follows : 



S]3hxrotilus natans vel Cladothrix natans belongs to the genus 

 Cladothrix and the family Chlamydobacteriaceae. 



S. natans forms slimy masses in factory waters and streams, 

 and in this species there are many parallel hyphae, each surrounded 

 by a gelatinous sheath. 



From personal observation the opinion was formed that there 

 are four different types of organism, which have been hitherto 

 described under the designation of S. natans. This paper deals 

 with the Sphserotilus group only, since the similar organisms of 

 the Cladothrix class, notably C. dichotoma, are really members of 

 the general class of iron bacteria, while >S'. natans is a polysaprobe 

 associated with running water polluted by sewage : and while 



EXPLANATION OF PLATE XX. 



Fig. 1. — Sphserotilus natans. "Microscopic Water Analysis," Mez. This is 



identical with the author's Sphierotilus A. 

 ,, 2. — Ditto. "The Examination of Waters for Water Supplies," Thresh. 



This difiers from the Sjphxrotilus natans of Mez., and is identical 



with the author's Sphserotilus B. 

 ,, 3. — Ditto. " Sphserotilus natans,'' Wilson and Johnson. In the original 



plate the sheath is not shown, but has been added by the author. 



This is identical with Sphserotilus B. 

 ,, 4. — Cladothrix dichotoma Ellis. This is inserted for comparison from the 



most recent and complete work on this organism. 

 ,, 5. — Sphserotilus A. 

 ,, 6. — Sphserotilus B. 

 ,, 7. — Sphserotilus C. 

 ,, 8. — Sphserotilus D. 



,, 9. — Characteristic cell of Sphserotilus A. 

 ,, 10. ,, ,, Sphserotilus B. 



,, 11. ,, ,, Sphserotilus C. 



,, 12. ,, ,, Sphserotilus D. 



,, 13. — Cladothrix dichotoma. Observed by the author. Compare 4. 

 ,, 14. — Ditto. Cell in transverse fission. Ellis. 

 ,, 15. — Sphserotilus B. Cell in transverse fission. Compare 14. 

 ,, 16. — Cells of Sphserotilus B. Exhibiting unstained portions, possibly a form 



of endospore. 

 ,, 17. — Ditto. Discharged from sheath with two unstained globules in each cell. 



