1. Reduction of competition for food stimulates both natality and survival.

2. The height of the jejunal villus increased from natality , peaked in the postnatal 3rd month and decreased from then on.

3. The essence of education is natality. Schools and educational institutions should be protected by the adults, free from any political and social interference.

4. Nntality is the birth of new individuals. The realized natality is the actual successful reproduction per female over a period of time.

5. The effect of crowding and physiological stress and shortage of food resources were the main reasons for the decline of population natality and yearly increase rate.