NOTES ON CERTAIN PARASITIC PROTOZOA 



21 



conceivable even probable. The spirochsetae, when joined end- 

 wise in pairs, can move in the direction of either extremity. 



Agglutination occurs when the conditions are unfavourable to the 

 full vitality of the parasites, the hinder i.e., the non-flagellated 

 ends cohering as shown in Fig 5, i and k. The same mode of agglu- 

 tination has been observed in T. Lewisi by Mesnil and Laveran 

 (see Part I., Fig. 78). In the T. nociuce it is by cohesion of 



FIG. 4. SPIROCH^TA ZIEMANNI. THE GROWTH AND SUBDIVISION OF THE 

 ASEXUAL OOKINET IN THE GNAT'S INTESTINE. (After Schaudinn.) 



i, The ripe ookinet ; the nucleus contains a centrally placed body which is con- 

 stituted by sixteen chromosomes, in the midst of which is a centrosome. The 

 peripheral chromatin is also composed of sixteen chromosomes. 2, Shows the 

 ookinet elongated in a spiral and with four nuclei, two of which are in process 

 of division ; 3, the ookinet greatly elongated and rolled into a multi-nucleated 

 ball ; 4, the same ookinet, its coils fused into one body, which is giving off 

 peripheral nucleated buds that are changing into minute flagellates or 

 spirochretas. 



the anterior flagellated ends that the rosette-like clusters are 

 formed. 



We must consider with the closest attention Schaudinn's descrip- 

 tion of the multiplication of these parasites in the body of the gnat. 

 The minute trypanosome, seen more highly magnified in a, divides 

 longitudinally, as at b ; the division may be incomplete for a time, 

 leaving pairs attached end to end as at c and d. The spirochsetes may 



