It is, of course, impossible to prescribe boundary lines for a poet, although there are critics who seem to enjoy staking out a poet's claim. While I have no intention of building futile walls around Mr. Frost's garden, nor erecting a sign with the presumptuous prohibition of trespassing beyond them, it is clear that he has himself chosen to excel in quality of produce rather than in variety and range. In the first poem of the first volume, he concludes as follows: They would not find me changed from him they knew-- Only more sure of all I thought was true. This is certainly a precise statement of the impression made on the reader who studies his three books in chronological order. _A Boy's Will,_ as befits a youth who has lived more in himself than in the world, is more introspective than either _North of Boston_ or _Mountain Interval;_ but this habit of introspection gave him both the method and the insight necessary for the accurate study of nature and neighbours. He discovered what other people were like, simply by looking into his own heart. And in _A Boy's Will_ we find that same penetrating examination of rural scenes and common objects that gives to the two succeeding the final stamp of veracity. I do not remember ever having seen a phrase like the following, though the phrase instantly makes the familiar picture leap into that empty space ever before the reader's eye--that space, which like bare wall-paper, seems to demand a picture on its surface. _Or highway where the slow wheel pours the sand._ It is fortunate that the law of diminishing returns--which every farmer is forced to heed--does not apply to pastoral poets. Out of the same soil Robert Frost has successfully raised three crops of the same produce. He might reply that in the intervals he has let the ground lie fallow--but my impression is that he is really working it all the time. The sharp eye of the farmer sees nothing missed by our poet, but the poet has interpretation as well as vision. He not only sees things but sees things in their relations; and he knows that not only is everything related to every other thing, but that all things are related to the eternal mystery, their source and their goal. This is why the yellow primrose is so infinitely more than a yellow primrose. This also explains why the poems of Mr. Frost, after stirring us to glad recognition of their fidelity, leave us in a revery.