We called, on the way to Dr. Gray's, at the bouse of Professor Longfellow; then visited the extensive nurseries of C. M. Hovey & Go. Their pear-trees, both dwarf and standard, are among the best we have ever seen, and produced fine results in 1856. Mr. Hovey is a firm believer in dwarfs, and those who know him, know with what enthusiasm he enforces a favorite theory. In the morning we had found him superintending a large show of fruits and flowers in Boston at the weekly exhibition, and here he was again directing and Superintending one of the most extensive commercial establishments in the Union, one, indeed, that has exercised no inconsiderable influence on our country's progress. We noticed here the new strawberries, Sir Harry, Sir Charles Napier, and Admiral Dundas, which have been so popular abroad. We noted also, a new Lantana, Lutea Superba, which will command attention, as will Ardisia fructo alba, and a hardy Erica, . vulgaris, which withstood the dreadful winter of 1855-56. Mr. Hovey has a new seedling Arbor vitas, somewhat like Aurea, but which promises to be more valuable; many seedling varieties of Azaleas, yellow, etc, and hardy; he has found Cephalotaxus and Podocarpus hardy.

A new weeping elm, a cut-leaved oak, and the weeping fountain willow, a new and most beautiful tree, the purple sycamore, etc. etc. etc, we find noted in our hasty pencillings. and here, as well as at Dr. Gray's, we saw with great admiration the neglected Rhododendron punctatum, a native variety, loaded with flowers, and of a pendulous habit. Mr. Hovey has a fine stock of Siberian Arbor vitae, and also of Yirgilia lutea. In short, this establishment deserves well of the country, and is to Boston what Mr. Buist's is here - a never-failing resource for new plants. Every department receives attention, though, of course, there are specialities, which they attend to more as personal matters, than as nurserymen. Among fruits, the speciality is the Pear, of which they have an immense collection, including every, known variety to be found in France, Belgium, or England, and of native kinds by far the most complete collection, embracing over one hundred sorts. Nothing remains to be added but the new kinds, as they yearly make their appearance.

But they pride themselves on their collection of specimen trees, numbering twenty-Jive hundred, the oldest planted in 1842; these are all bearing trees, planted round the grounds, and not through them. The crop of pears in 1856 was 500 bushels, quite equal to any produce in Europe.

Of apples, they have one long walk, bordered on each side with 800 trees, of that number of varieties, and now just coming into bearing; they were set out in 1844, but as they prune them in to make dwarfs of them, they are very slow in bearing.

Among shrubs, their speciality is the collection of "American Plants," as the English call them, viz: Rhododendrons, Azaleas, etc. No such collection is to be found except at Bagshot, and the great American plant growers around that part of the vicinity of London. They have many hundred flowering plants of all the best Belgian and English hardy sorts, and thousands of seedlings of their own. The ground is peaty (one part of it), and they grow in perfection.

Among hardy plants, a speciality is the herbaceous Paeonies, of which they have great quantities, including the very latest new ones; and another, and perhaps greatest of all in the ornamental department out-doors, is their Japan lilies, of which they had two beds of 1000 bulbs, embracing some of the finest seedlings yet known. One bed was a treat well worth going from Philadelphia to see. These are favorite flowers, and much time has been devoted to the production of new sorts by hybridization with the native hardy and old Tiger species; these seedlings partake of the hardy character of those, while they are far more brilliant than the imported Japan plant.

In doors, the speciality is the Camellia, of which they have a most extensive collection of some 300 varieties, and upwards of twenty seedlings, among which are some very superior kinds. Two of them they intend to offer for sale this year; one is a remarkable production, having flowers of four colors on the same plant, and holding that character now in the fifth year of its flowering. Another is almost a scarlet; the Mass. Horticultural Society gave them the medal of $60 for this about three years ago. Drawings of them will soon be sent out. Such are some of the more prominent things noted at this establishment, where, however, they do not neglect any of the numerous classes of plants which make up a collection.

In our next "ramble," we shall be obliged to change onr locality, having, for the present, exhausted onr Boston notes, without having mentioned a tithe of its horticultural importance. We neglected to take notes of exhibitions of the Massachusetts Horticultural Society, but they are published, and such lists will scarcely keep.