ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 529 



he has studied. 1. All possess an elongate and more or less spirally 

 wound body, which is non-cellular. 2. They are flexible, the degree of 

 flexibility displayed differing in different species. 3. Antero-posterior 

 polarity is absent in all genera. In other words, during movement 

 either end of the body may function as an anterior or posterior end. 

 4. The body is clothed with a pellicle, the thickness of which differs in 

 different genera. (In the smallest species of Treponema and Spirocheeia 

 the presence of a pellicle cannot be established with certainty.) 5. All 

 the Spirochffits which are sufficiently large for accurate observations to 

 to be made in this respect areplasmolysahle. (The results of plasmolysis 

 are not identical in all forms. The differences observed appear to be 

 due to correspoiiding differences in the thickness and nature of the 

 pellicle.) 6. No flagella or other special organs of locomotion are 

 present. 7. The cytoplasm possesses (in the larger forms at least) a 

 peculiar " chambered " structure, and there is probably a form of 

 chromidial nucleus present. 8. In Cristispira there is a peculiar axial 

 thickening of the pellicle — the crista, which may be the homologue of 

 the axial fibre of Spirochseta pUcatilis. 9. Metachromatic granules 

 (" volutin " granules) are present in Cristispira, Saprospira, and Spiro- 

 chseta, and possibly in Treponema also. 10. Colouring matter (chromo- 

 phyll) is absent. 11. Cyanophycin granules are absent. 12. The 

 method of multiplication is always by transverse division — simple in 

 Cristiftpira and Treponema, multiple in Saprospira and Spirochseta. 13. 

 Correlated with this method of multiplication there is a marked peculiarity 

 IB the variation of the dimensions of the body in all four genera of the 

 Spirochaits. The individuals of any species show a considerable varia- 

 bility in length — due to growth in one dimension of space — but not in 

 breadth. There is no conclusive evidence of any spore-formation or 

 sexual process. 



If the Spirochfets be compared with Flagellates, their only common 

 characters are those numbered 2, 4, 9, 10, 11, which are common to any 

 Protista. The differences are much greater. The combination of 

 characters numbered 1, 3, 5, 7, 8, 13, does not occur in any known 

 Protozoon. There are, however, striking resemblances between Spiro- 

 chfets and Bacteria (characters 1, 3, 4, 5, 9, 10, 11, 12, 13), and the 

 author ranks the Spirochfets as a group of Haplobacteria, beside Coccoidea, 

 Bacilloidea, and Spirilloidea. 



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