140 DISCUSSION
sore occurring in camel-using countries, he (Captain Patton) had had a good deal of experience with Arab camel-drivers who frequently suffered from similar sores on their legs and sometimes on their faces. By Oriental sore he meant a sore in which the characteristic parasite {H. tropica) had been found. Arabs of the Aden Hinter- land often developed these sores after the bites of Ornithodorus savignyi, and he had examined a large number of scrapings from these sores, but had never been able to find any parasites. He contended that the sores occurring in camel-using countries were not neces- sarily true Oriental sores, and that that term was used far too loosely. His observations were quite in agree- ment with those of Sir Havelock Charles, that kala-azar and Oriental sore were two distinct diseases.
Dr. Wenyon had drawn attention to the difficulty of drawing a hard and fast line between herpetomonas and trypanosome. He (Captain Patton) was well aware that trypanosomes when cultivated in test-tubes showed multiplication forms not unlike young herpetomonads ; from this he thought it was only possible to say that trypanosomes had at some time or other evolved from herpetomonads. It should, however, be noted that it had not yet been proved that the well-known vertebrate trypanosomes pass through multiplication stages similar to herpetomonas and crithidia in the intestinal tract of blood-sucking invertebrates. A true herpetomonas or a crithidia, however, never became a typical trypanosome. With regard to the flagellates of leeches, he had found that a leech common on frogs in Madras had a crithidia of its own which was in no way connected with the frog trypanosomes ingested by the leech.
Sir Patrick Manson had criticized his observations on the development of H. donovani in the bed-bug {Cimex
