L.--The part of the straw used for platting; that part of the stalk which is _above the upper joint_; that part which is between the _upper joint_ and the seed-branches. This part is taken out, and the rest of the straw thrown away. But the _whole plant must be cut and bleached_; because, if you were to take off, _when green_, the part above described, that part would wither up next to nothing. This part must die in company with the whole plants, and be separated from the other parts after the bleaching has been performed. M.--The time of cutting must vary with the seasons, the situation, and the sort of grass. The grass which I got in Hertfordshire, than which nothing can, I think, be more beautiful, was, when cut, generally in _bloom_; just in bloom. The _wheat_ was in full bloom; so that a good time for getting grass may be considered to be that when the _wheat is in bloom_. When I cut the grass in Sussex, the _wheat was ripe_, for reaping had begun; but that grass is of a very backward sort, and, besides, grew in the _shade_ amongst coppice-wood and under trees, which stood pretty thick. N.--As to the sorts of grass, I have to observe generally, that in proportion as the colour of the grass is _deep_; that is to say, getting further from the _yellow_, and nearer to the _blue_, it is of a deep and _dead yellow_ when it becomes straw. Those kinds of grass are best which are, in point of colour, nearest to that of wheat, which is a fresh pale green. Another thing is, the quality of the straw as to _pliancy_ and _toughness_. Experience must be our guide here. I had not time to make a large collection of sorts; but those which I have sent to you contain three sorts which are proved to be good. In my letter of the 3d instant I sent you _sixteen_ pieces of plat and _eight_ bunches of straw, having the seed heads on, in order to show the sorts of grass. The sixteenth piece of plat was American. The first piece was from _wheat_ cut and bleached by me; the rest from _grass_ cut and bleached by me. I will here, for fear of mistake, give a list of the names of the several sorts of grass, the straw of which was sent with my letter of the 3d instant, referring to the numbers, as placed on the plat and on the bunches of straw. PIECES BUNCHES SORTS OF PLAT. OF STRAW. OF GRASS. No 1.-- No. 1. --Wheat. 2.} { Melica Caerulea; or, Purple Melica 3.} 2 and 3 { Grass. 4.} { Agrostis Stolonifera; or, Fiorin Grass; 12.} 4 and 12 { that is to say, one sort of Couch-grass. 5.} 10.} 5 and 10 Lolium Perenne; or Ray-grass. 6.} { Avena Flavescens; or, Yellow Oat 11.} 6 and 11 { grass. 7.} { Cynosurus Cristatus; or Crested 15.} 7 and 15 { Dog's-tail grass.