PTROPLASMA MURIS. 507 



Rogers (42, 43) and others (4, 5, 6) have obtained flageUated 

 organisms from cultures of the Leishman-Donovan bodies. 

 These flagellates are obtained in an essentially artificial 

 medium, namely, by mixing infected spleen blood with sodium 

 citrate and slightly acidifying with citric acid. In nature 

 flagellate stages of these bodies, probably similar in character 

 to those obtained in .artificial media, might occur in the ali- 

 mentary canal of an Arthropod, but have not as yet been 

 observed. It would seem, then, a little premature to refer 

 these flagellates, developed in citrate cultures, to the genus 

 Herpetomouas, as the " Herpetomonas of kala-azar," 

 Rogers (43) .^ 



Apparently flagellates have not yet been obtained from 

 cultures of the similar Cunningham- Wright bodies of Oriental 

 sore (7, 35, 52). 



A true Piroplasma possesses only one ~ chromatin body, and 

 no typically flagellated stages are yet known in its life- 

 history. 



Koch (21) has recently published some short, but stimu- 

 lating observations, on stages of P. bigeminum in the gut 

 of ticks just gorged with infected bovine blood, and in tick 

 eggs, observed in Grerman East Africa. He states that the 

 Piroplasraata in blood-corpuscles taken into the alimentary 

 canal of ticks already, or very soon, show division of their 

 chromatin into two, and that radial processes are developed 

 from the parasite after it leaves the blood-corpuscle. Similar 

 radiate forms are mentioned in the case of P. parvum. 

 Later, copulation stages (probable zygotes) of the Piroplasmata 

 are seen in the alimentary tract of adult ticks. Large pear- 

 shaped forms of the parasite are described from tick eggs. I 

 have myself seen similar forms in eggs of ticks infected with 

 P. can is. There are no recorded observations of the para- 

 sites in larvae and nymphs of ticks. 



• Unfortunately Rogers, in bis paper, writes of the "group Hepatomonas," 

 apparently in mistake for the genus Herpetomonas. 



- See Addendum for remarks on Liihe's researches, and the presence of a 

 blepharoplast in P. can is. 



