| Abstrakt: |
It has been stated by observers that a certain species of trypanosome may show differences in size according to the host infected. An examination of the literature however reveals much divergence of opinion concerning this matter. In addition such statements as appear are very fragmentary. The technique upon which some of them are based moreover leaves much to be desired.Plimmer and Bradford1(1898) quoted by Castellani and Chalmers remark that the length of Trypanosoma bruceiis constant for a given animal but varies in different hosts, being between 26 and 27 micra in rats, mice, guinea pigs, rabbits and dogs. Kanthack, Durham and Blandford2state that the Nagana parasites vary considerably both in size and in form. Bruce, Hamerton and Bateman3come to the conclusion that Trypanosoma bruceivaries from 10 to 16 micra in length in the rat with an average of 13.0 while in guinea pigs the limits are 8 to 16 micra with the average 12.5. Laveran and Mesnil4claim that their own work which included parasites from a large range of mammals shows no manifest variation in size of the organism.A culture of Trypanosoma bruceiwas obtained from Dr. F. G. Novy at the University of Michigan. Immediately upon receipt, it was suspended in sterile physiological saline and injected, subcutaneously into a white rat. In order that some carefully collected data might be acquired concerning possible variations in the size of the micro-organism in the rat and in the guinea pig, blood from this animal very shortly after death was injected into a guinea pig. Heart blood from this guinea pig at the time of its autopsy in turn was injected into another guinea pig and also into a white rat. |
