APPENDIX. 441 



(i) The Spirillum Obermeieri is an exceedingly delicate, flexile 

 spiral_ of from ten to twenty turns. It is found in the blood of patients 

 suffering from relapsing fevers. It is from 16 to 40^ in length, and is 

 usually less than half the diameter of the cholera bacillus. According to 

 Koch and Vandyke Carter these organisms can only grow in the blood 

 inside the body, although they may be preserved alive for a considerable 

 length of time in blood serum or in normal salt solution. When the blood 

 of patients suffering from relapsing fever (during the febrile stage) is inocu- 

 lated into the long-tailed macacus monkey an attack of fever is set up, 

 during which the spirillum can be demonstrated in the blood. It may also 

 be demonstrated in the blood vessels of organs removed from animals killed 

 during this febrile attack. There are no relapses in .the monkey as in man, 

 but one attack of the disease does not protect against a second. 



(2) Sfirochate plicatilis is an organism of extraordinary length — no to 

 225/t. It is extremely motile, and occurs in stagnant pools in which there is 

 decaying organic matter. The threads are arranged in long wavy lines, the 

 long waves appearing to be cut into shorter waves ; these, of course, are 

 merely the spiral turns. 



(3) Spirillum tenue is an exceedingly short spiral of from 1.5 to 5 turns 

 of a screw. The length of the organism is from 4 to 15^. It usually 

 occurs in vegetable decoctions, in which it darts about with very great 

 rapidity 



(4) Spirillum serpens consists of thin threads, which interlace to form a 

 kind of network. The organisms are from 11 to 28/1 in length, and 

 usually have from three to four regular wave-like turns. It is often found 

 in stagnant pools and where there is decaying vegetable matter. It is 

 about i^ in thickness. Where the felting is very marked it may some- 

 times appear to be united in chains. It moves about rapidly. 



(5) Spirillum undula. — Sometimes thicker than the above, but not so 

 long, though the average length is greater. Length 8 to 12/j, and breadth 

 I.I to 1.4;/. The spirals are well marked, but they seldom consist of more 

 than about three turns. There are usually distinct flagella at the ends 

 (fig. on p. 29). .Like the other forms, it occurs in putrefying fluids. 



(6) Spirillum volutans is much longer and thicker than any of the pre- 

 ceding forms.- It is 1.5 to z\i in thickness and 20 to 30/^ in length. The 

 ends are somewhat thinned and rounded. The protoplasm contains a 

 number of dark granules ; there is a distinct flagellum at each end. This 

 spirillum may be motile, but very frequently it is perfectly motionless. It 

 has been found in marsh water, and also in a decoction of dead fresh-water 

 snails. 



(7) Spirillum rugula consists of short cells or single wavy bacilli 6 to 8/t 

 in length and .5 to 2.5/« in thickness. They have usually a single bend or 

 a short flat turn ; may hang together in chains or form a felted mass. They 

 are extremely motile, and rotate round their own axis. They are provided 

 with flagella, and form spores at their ends very much as does the tetanus 

 bacillus, having then very much the appearance of a. comma. Found in 

 marsh water and very frequently in the alimentary canal ; probably anaerobic 

 in character, and, according to Prazmowski, sets up decomposition of cellu- 

 lose. 



