Paterson, C.L.Bezuidenhout, J. DürrBigalke, R.D.2015-03-262015-03-2620141986Prozesky, L, Bezuidenhout, JD & Paterson, CL 1986, 'Heartwater: an in vitro study of the ultrastructure of Cowdria ruminantium’, Onderstepoort Journal of Veterinary Research, vol. 53, no. 3, pp. 153-159.0330-2465http://hdl.handle.net/2263/44163The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.Notwithstanding morphological differences, the ultrastructure of Cowdria ruminantium cultured in vitro concurred to a large extent with that in previous in vivo studies. Two distinct forms of the organism, elementary and reticulate bodies, and a 3rd group of intermediate organisms were identified. Organisms within a particular vacuole were generally a specific form, but in cells containing many colonies different forms were present in the same colony. Most organisms were enveloped by 2 membranes and a few were surrounded by a 'capsule'. C. ruminantium multiplies mainly by binary fission, but it appears that multiplication can also take place by means of budding. The taxonomy of C. ruminantium is briefly discussed.en©ARC - Onderstepoort and Faculty of Veterinary Science, University of Pretoria (original). ©University of Pretoria. Dept. of Library Services (digital).Veterinary medicineVeterinary medicine -- South AfricaArticle