At present, we have only knowledge of the molecular and biochemical events that occur during leishmania development and that are suggested by the ultra-structural studies. Other studies of leishmanial morphogensis are handicapped by our inability to studies the growth of the parasites in culture and in animals. Firstly the cytoplasm divides from the anterior flagellar end to the posterior end. Secondly, four daughter cells can be seen attached by the still dividing cytoplasm. The ingested parasite then protects itself in a variety of ways against these host defence mechanisms.
Taxonomy is essentially the recognition of different organism and their separation into groups.
The recognition and grouping are based on morphological, biochemical and molecular biological criteria of the species of the leishmania. A variety of very different types of leishmanial parasites have been discovered in humans and other mammals. The early system of designating leishmanial species according to the clinical conditions that they cause in humans has been modified because it has been recognised that some leishmania cause more than one type of clinical condition. To accommodate current knowledge of the relationship between leishmania infections and diseases, new system of nomenclature and taxonomy have been developed based on the antigenic, genetic and biochemical characteristics of the parasites. Once a distinct species is defined, reasons may be found for separating its members into subspecies based on variation among populations within it.