1. Sepals 5, petaloid , white, pink-red, or green, usually persistent.

2. Result:The petaloid toenails had approximately 3 types such as the clarity, the amalgamation and the degeneration.

3. Analyzing the data of 26 nuclear families and 1 family with 3 generation, it was found that the petaloid toenail had the same hereditary characters as the dominant single-gene trait.

4. Analyzing the data of 51 nuclear families and 2 families with 3 generations, it was found that petaloid toenail had the same hereditary characters as a dominant single-gene trait.

5. The residence time in the filtration chamber and the decomposition of the molten object are reduced because of the petaloid inner walls of the filtration chamber.

6. Petaloid toenails, a human trait where the nail of little toe appears petaloidly exists in many populations of the Han Nationality in North China.

7. The authors consider that increasing the piston stroke is an effective scheme, and point out that the petaloid combustion chamber has a good adaptability.

8. Objective: To research the types, the distributions for gender and age, and the hereditary mode of the petaloid toenails.

9. The main finger ring (1) is fastened in the petaloid ring plane (22) to form a combined finger ring.