HEKPETOMONAS ASPONGOPI 



203 



occasions iu the ficccs. They are oval, round, or pear-shaped bodies (Fig. 37, a) 

 measuring from 1 /n to 2 /i in length. Their protoplasm stains blue and in parts is very 

 finely vacuolated. These round bodies contain two large nuclei somewhat diffuse iu 

 structure. Nearly the whole of the cell is taken up by the nuclei. A general enlarge- 

 ment of this resting body is the first stage towards further development. The two 



M. — Sti'uctui-e and life-cy 



It iiMl (■ I'lviaion of restinfi ata$e sliowiuii (our nuclei. 



if, c :tn'l / Vi im§ form somewhat resembling !i Leisbman-Donovuu 



body. 

 ^ ;iU'l /: I wo youn^ forms with fla^ellu. 

 i and J Two young forms showinfi division of blepbaroplast and 



flagella. 

 .ill \.\i<^ drawinii* were made Willi a camera lucida. 



.le ei llcr/fctot/ioitas as/'oitgo/'i 



k Youn$ form witli IjIepliai-ojilasL aud macronueleuh divided. 



/, in and H Adult fla§ellatea 



(7 an.:! p Lon^ thin form of adult flagellate. 



q Dividmg form with inacronucleUH divide.i 



r ao'l ^ Dividing forma with Tnaeronueleus, bl i i i 



fia^ellum divided, 

 / and K Last statues of division. 

 Magnification : ^\ oil iirimcrsron ami 4 cyc-pitxc (Zeiss) X 940 



large nuclei divide, thus forming four nuclei (Fig. 37, h and c). Immediately after this 

 the cell divides by transverse fission. In this last stage one of the nuclei decreases in 

 size and probably becomes the blepbaroplast of the young immature parasite (Fig. 37, 

 d, e and f). I have constantly found these bodies present in my preparations and believe 

 that they are the resting stage of Herpetomonas aspongopi, but as they were only found 

 in the fajces on two occasions it is possible that their significance may have been 

 mistaken. The young immature parasite is generally pear-shaped, and however formed 

 is easily recognisable (Fig. 37, d and e). Its nucleus stains pink and is situated at the 

 rounder end of the parasite. The protoplasm stains blue and may appear somewhat 

 vacuolated. When highly magnified, indefinite chromosomes can be made out, but it is 

 not possible to count them. In the young parasites the blepbaroplast measures about 

 one-third the size of the nucleus ; it is almost always circular in shape and stains deep 

 red. Owing to its great affinity for the stain no inner structure could be demonstrated. 

 There was no other structure visible in these young forms. In the next stage the young 

 parasite appears larger. Its form is elongated and the flagellum grows out from the 

 micronucleus (Fig. 37, g and h). Division by longitudinal fission may now commence 

 (Fig. 37, / and j). The parasites now rapidly become elongated until the adult stage is 

 reached. 



A typical adult parasite (Fig. 37, I, m. and n) measures about 18 ^i in length and from 

 2 ^1 to 3 fi iu breadth at its widest part. Its posterior end is usually somewhat pointed, 

 although I have seen a few with blunt ends. The body is cylindrical with a blunt 

 anterior end. The protoplasm stains very evenly, there being no vacuolated areas. One 



Resting stage 



