Evrimsel dizimde gerçek sinaptik sinir sistemine İlk defa rastlanan bir organizma olan yasmkurtlarla yapılan bu araştırmada, bu hayvanların klâsik şartlanma imkânları ve re jenerasyonu müteakip hatırlama tasarrufları incelenmiştir. Ayrıca, reserpine, tetracycline ve thymidine gibi kimyasal maddelerin gerek genel davramşlar ve gerekse Öğrenme performanslarına etkileri yönünden araştırmalar yürütülmüştür. Memleketimizde bulunan ve çok gözlü bir tür olan Polycelis tenuis ile, iki gözlü bir tür olan Dugesia lugubris'ien elde edilen neticeler temel bilimler yönünden olumlu teorik ve pratik nitelikler göstermektedir. >  

The flatworm (planarian) may be considered as an extremely significant organism from the standpoint of evolution. It stands at the bottom of bilateral animals, and is characterized by a marked bilateral symmetry wit h a differentiation of the anterior end as a head. True synaptic nervous transmission and definite encephalization appear for the first time in the planarian. An even more striking aspect of this animal is its remarkable powers of regenaration. These characteristics, thus, introduces the planarian as an important subject in the study of behavioural processes. Thompson and McConnell's (1955) experiments of classical conditioning wit h these flatworms generated great interest and controversial opinions about their learning capacities (Mc Connell et al, 1955, 1959, 1964; A.L. Jacobson 1964; R.L. James and E.S. Halas 1961, 1962, 1964, Mc Connell 1965, E.L. Bennett and M. Calvin 1964). It should be interesting to investigate the different behavioural characteristics of some of the species found in Turkey. For this purpose, two local species of planaria, Polycelis tenuis (Ijima) (1884) and Dugesia lugubris (Schmidt) (1861) were selected and several series of experiments were conducted in our Psychological Laboratory. The first of these was the application of classical conditioning experiments to these animals. Theability to be conditioned which were found in many subhuman species may also be challenged with the planaria since they possess a central nervous system of a rudimentary character. I n our experiments electric shock was used as the unconditioned stimulus (Su) and light as the conditioned stimulus (Sc). (Rc) or the conditioned responses are the natural responses of the planarian to the electric shock, such as, stopping, turning of the cephalic region and longitudinal contraction. After repeated presentations, these natural responses to the electric shock were also expected to be elicited to light. Thirty two planaria were studied. Fourteen were of the species Polycelis tenuis and eighteen were of the species Dugesia lugubris.