FLAGELLATA I 2 I 



It would seem probable that the virulence of the Persian Tick 

 (Arc/as persica) is due to similar causes. The Indian maladies known 

 as " Kala Azar " and " Oriental Sore " are cliaracterised by blood 

 parasites, at first called after their discoverer the " Leishman 

 bodies," which have proved to be the effects of a Piroplasma. 



Trypanosoma is distinguished by the expansion of its flagellum 

 into an undulating membrane, that runs down the edge of the 

 body, and may project behind as a second lash. In this mem- 

 brane run eight fine muscular filaments, or myonemes, four on 

 either surface, within the undulating membrane ; at their lower 

 end they are all connected with a rounded Body, the " blepharo- 

 plast," which is here in its origin, as well as in its behaviour in 

 reproductive processes, a true modified nucleus, comparable in some 

 respects, as was first noted by Plimmer and Eose Bradford,-' with 

 the micronucleus of the Infusoria. Part of the segmentation 

 spindle persists in the form of a filament uniting the blepharoplast 

 with the large true functional nucleus (Fig. 39, a-f). 



The blood of patients suffering from relapsing fever contains 

 a fine wriggling parasite, which was described as a Schizomycete, 

 allied to the bacteria, and hitherto termed Spirochaeta olermeieri. 

 Schaudinn has shown that this and other similar blood parasites 

 are closely allied to Trypanosoyna; and since the original genus 

 was founded on organisms of putrefaction which are undoubtedly 

 Schizomycetes, Vuillemin has suggested the name Treponema. 

 T. pallidum is found in syphilitic patients, and appears to be 

 responsible for their illness.^ 



The Craspedomonadidae (often called Choanollagellates, Fig. 

 40) are a group whose true nature was elucidated some forty 

 years ago by the American zoologist, H. James-Claak. They are 

 attached either to a substratum, by a stalk produced by the base 

 of the cell, or to other members of the same colony ; they are 

 distinguished by the protrusion of the cytoplasm around the 

 base of the single flagellum into a pellucid funnel,^ in which the 

 plasma is in constant motion, though the funnel retains its shape 

 and size, except when, as sometimes happens, it is retracted. 



1 Quart. Journ. Micr. Sci. xlvi. 1902. 



2 A Zambezian Tick infects man with a Treponema, producing relapsing-fever ; 

 another species is found in the tropical disease "framboesia " ("yaws" or "parangi"). 



' Stated by Geza Entz and Raoul Franc^ to be due to the spiral twisting of a 

 plasmic membrane, and to be like a cone formed by twisting paper, with the free 

 edges overlapping. 



