GENERAL CHARACTERS OF SPIROCELETES. 69 



almost exactly the appearance of true spirochaetes (Fig. 

 55) . The reason for regarding them as artifacts is that 

 none were seen in other specimens of the same material 

 and that their arrangement often in crosses or radiat- 

 ing lines is peculiar ; but their resemblance is so exact 

 that, if this view be correct, doubt may be thrown on 

 many descriptions of spirochaetes given by other 

 writers. 



Objects somewhat resembling spirochaetes are the 

 male gametes of some protozoa (coccidium, plasmodium) , 

 the flagella of trypanosomes which may occasionally be 

 found free (Fig. 56), and attenuated forms of these last 

 organisms and of Herpetomonas or Leishmania. The 

 appearances found by Karlinski in a macerated pig- 

 fcetus and figured by Baling (Fig. 57) may be either real 

 or simulated spirochaetes. 



CLASSIFICATION. 



It has already been pointed out that the position of 

 the spirochaetes in nature whether they are to be re- 

 garded as protozoa or bacteria is doubtful. Their 

 relations as a group are almost equally undecided. 

 The resemblance of the smaller to the larger spirochaetes 

 is not very close. Indeed, while each of these groups 

 is fairly well marked, the relationship between the two 

 is almost less striking than that of the smaller organisms 

 to a group of bacterial organisms the large spirilla. 

 The Sp. obermeieri was originally classed with these, and 

 it seems not impossible that this view is more correct 

 than the recent classification of these little organisms 

 with the spirochaetes. 



Certain peculiarities observed in the Sp. pallida 

 led Vuillemin and afterward Schaudinn to separate it 

 from the other small spirochaetes and to put it in a dis- 

 tinct genus, called by the former Spironema and by the 



