Intracellular Rickettsia -like Micro-organisms in Certain Ticks

LITTLE attention has been paid to the intracellular Rickettsia -like micro-organisms in acarines. Perhaps the first approach to a comprehensive survey on these organisms in ticks was that of Cowdry 1 , although a few earlier observations were made 2–4 . Cowdry reported the occurrence of intracellular micro-organisms, of rickettsial nature, in the malpighian tubules and in eggs of several species of ixodid and argasid ticks. He pointed out that, being present in eggs and unfed larvæ, the organisms were transmitted by inheritance, and postulated a symbiotic function. Further work on the morphological appearances of such micro-organisms and their distribution in the malpighian tubules and oocytes of some of these tick species were developed by Buchner 5 , Mudrow 6 and Jaschke 7 .