Parabita (from the Greek. para - around, around, and bioo - live) - two (or more) of animals, interconnected by means of surgical intervention. As Paramonov increasingly using rats and mice, rarely rabbits and dogs. In an acute experience P. create cross-connection carotid artery and jugular veins of the two animals. In chronic experience create a skin-muscle-abdominal anastomosis. It is established that the rate of exchange of blood in the first case is about 4-5 ml/min, and in the second - 0,05-0,1 ml/min Parabita used to determine ways to spread the infection of one of the partners, to study mechanisms of regeneration and hypertrophy of the kidneys, liver and some endocrine glands. One of the major drawbacks of this method is the relatively high mortality P. in chronic experiment, although some parabita can live more than a month. The causes of death is not yet clear, but seems to be connected with the tissue incompatibility (see), much more clearly manifested in transplantation.