510 Dr. H. B. Fantham. Herpetomonas pediculi, n. sp., [Nov. 24, 



Morphology. 

 A. The Pre-fiagellate Stage. 

 The pre-flagellate stage (figs. 1-4) of H. pediculi, at its earliest, takes 

 the form of small oval or rounded bodies, measuring 6 /a to 7 fx by 4 fj. to 5 /x. 

 They have a marked resemblance to the Leishman-Donovan bodies. The 

 pre-flagellate shows a thin ectoplasm and endoplasm containing refractile 

 granules. The nucleus (fig. 1) is oval or occasionally rounded, while the 

 deeply staining blepharoplast (kinetic nucleus) may be bar-like, oval, or 

 occasionally rounded, and is well marked (figs. 1, 2). The position of 

 the blepharoplast varies somewhat, as would be expected in a developing 

 organism. It may lie to the side of the nucleus or above it, and occasionally 

 the blepharoplast is apposed to the nucleus. The chromatophile area 

 (fig. 1) from which the flagellum differentiates is also present. Division 

 occurs in the pre-flagellate stage (fig. 5), more especially when the organism 

 is beginning to elongate, and possesses a short flagellum. Isolated 

 chromatoid granules are sometimes present in the pre-flagellates (fig. 2). 

 The appearance of intermediate forms (figs. 2-4, 6, 7) between the pre- 

 flagellate and the flagellate has been indicated in the section dealing with 

 the life-history. 



B. The Flagellate Stage. 



The flagellate form (figs. 8-18) of H. pediculi is an active organism 

 relatively small compared with other Herpetomonads, its body length 

 varying from 11 /j, to 26 /i in the specimens examined. The inclusion of the 

 flagellum doubles the length of the organism, for the flagellum itself may 

 be 30 /j, in length (fig. 16). The cytoplasm of the organism is finely 

 alveolar (figs. 8-18), and very refractile in life. Chromatoid granules 

 (figs. 15, 18) are present in some cases. The protoplasm rarely presents 

 marked vacuoles in stained preparations, but in life a clearer area is some- 

 times seen near the origin of the flagellum. 



The nucleus (figs. 8-18) is round or oval, and crowded with very fine 

 granules. A karyosome is seen in some cases (figs. 11, 15) but is not visible 

 in all, doubtless being masked by the numerous fine granulations present. 

 A nuclear membrane apparently occurs, but is not so chromatic as when the 

 nucleus is of a vesicular type. The blepharoplast (kinetic nucleus) may be 

 oval or rod-like, lying transversely across the body, or somewhat obliquely. 

 Occasionally it is curved, and it often presents a bowed appearance prior to 

 division. It stains deeply, taking a purplish tint with Giemsa. Before the 

 onset of the multiplicative phase the blepharoplast presents no differentiation. 

 The free flagellum tapers finely at its free end. It originates as a rhizoplast 



