182 SPOLIA ZEYLANICA. 



rather difficult to demonstrate satisfactorily. There is little doubt 

 that in this case the differentiation marks off the male and female 

 gametes or gametocytes. 



The second parasite is a Hsemogregarine {H oemogregarina lesche- 

 naultii). — This creature has tM'o free motile forms always present in 

 the blood and two endocorpuscular forms. The one free form is a 

 slender creature with, the power of carrying out a truly amazing 

 set of gregarine movements ; it is also able to bend double and to 

 execute swimming or gliding movements. This creature has a 

 dense nucleus and pale protoplasm without granules ; it has an 

 exactly corresponding endocorpuscular form, which lies with one end 

 slightly curled up. 



The other motile foVm is massive and granular. This creature 

 moves much less actively than the slender form, and its periods of 

 rest alternate with periods of movements something after the fashion 

 of Coccidium Schuhergi, Schaudinn. 



There is a massive endocorpuscular form which is always rather 

 scarce ; I think it corresponds to the broad free form, but the nucleus 

 differs slightly. 



The third parasite of this gecko is a trypanosome {Trypanosoma 

 leschenaultii). — This trypanosome differs very markedly from Try- 

 panosoma pertenue ; I never found them together in one individual. 

 Cf. figs. 8, 9, and 13. 



All these gecko parasites were first sent me from Niroddumunai , 

 near Trincomalee, by Dr. WiUey. Later on, when I went over to 

 Trincomalee myself, I had the opportunity of studying them all in 

 the Hve state. The transmitting hosts were not discovered. 



Among the snakes only hsemogregarines were found. Zamenis 

 mucosus, the common rat snake, which lives on the roofs of houses, 

 and Chrysopelea ornata both showed a species with a very marked 

 capsule thickened at both ends. The hsemogregarine Hes in the 

 capsule, and often shows a deep red staining area at either end ; 

 the nucleus is rather delicate. 



Fig. 12. — I have not named this, as I notice that there is a 

 Hcemogregarina zamenis named by Laveran, and I have not yet 

 had the opportunity of seeing his description. There is a young 

 endocorpuscular phase Avithout a capsule, and a free motile form 

 also without a capsule. 



The cobra also showed a hsemogregarine ; possibly it wiU prove 

 to correspond with some of the already named species found in this 

 snake. 



A large python harboured a hsemogregarine, which was most 

 interesting on account of its extraordinary activity. The free form 

 moved with a rapid swimming motion, and was repeatedly seen to 

 enter a blood corpuscle by simply piercing it, to swim round between 

 the nucleus and the corpuscle wall, and burst the corpuscle by 



