直系继承人 meaning in English

heir of line
heir of the body

She replied , that he may have mercy upon him , and allow his noble soul to leave this yes , quite so , prince vassily continued impatiently , rubbing his bald head and again wrathfully moving the table towards him that he had just moved away , but in fact in fact the point is , as you are yourself aware , that last winter the count made a will by which , passing over his direct heirs and us , he bequeathed all his property to pierre
“对，是这样的， ”瓦西里公爵心情急躁地继续说下去，一面用手搓着秃头，愤愤地把推开的茶几移到身边来， “可是，到头来，到头来，问题就在于，你自己知道，去冬伯爵写了遗嘱，把他的全部产业留给皮埃尔，我们这些直系继承人都没有份了。 ”
The princess looked at him with the same dull immovable gaze . finally , we have to think of my family too , continued prince vassily , angrily pushing away a little table and not looking at her : you know , katish , that you three mamontov sisters and my wife , we are the only direct heirs of the count
“最后，还应当考虑考虑我的家庭， ”瓦西里公爵恼怒地推开自己身边的茶几，两眼没有望着她，继续说下去， “卡季什，你知道，你们马蒙托夫家的三个姐妹，可还有我的妻子，唯独我们才是伯爵的直系继承人。