By a man ' s finger - nails , by his coat - sleeve , by his boots , by his trouser - knees , by the callosities of his forefinger and thumb , by his expression , by his shirt - cuff - by each of these things a man ' s calling is plainly revealed 一个人的手指甲、衣袖、靴子和裤子的膝盖部分，大拇指与食指之间的茧子、表情、衬衣袖口等等，不论从以上所说的哪一点，都能明白地显露出他的职业来。
2.
However , only did a few pollen germinate in inter - specific hybridization between cerasus fruticosa and c . avian and many pollen tubes are crosswise on stigma and couldn " t penetrated into style . although a few pollen tubes entered , they couldn " t continue to grow due to accumulation of callosity in pollen tubes . in view of above - mentioned results , the irregular growth of pollen was the main reason to cause the incompatibility of distant hybridization between cerasus fruticosa and c . avium 而草原樱桃与欧洲甜樱桃种间杂交授粉后花粉在柱头上虽少量萌发，但花粉管在柱头上横向生长，或盘绕，扭曲不能伸入花柱；个别进入花柱的花粉管先端因沉积胼胝质而中途停止伸长未能进入子房到达胚珠，从而说明这种杂交授粉后花粉管的不正常行为是导致草原樱桃与欧洲甜樱桃远缘杂交不亲和的主要原因。
