Since the celebrated T. A. Knight and his contemporaries made, by their contributions to the Transactions of the Horticultural Society of London, a work of reference valuable for all time, we know of nothing approaching that series in excellence so nearly as this. It is really worth being a member of the Massachusetts Horticultural Society, though one lives hundred of miles from the place of meeting and never sees the exhibitions, even if they get nothing more for the annual subscriptions than these volumes. A society with a secretary like Mr. Manning is particularly blessed.

Bacteria, - the smallest of living organisms, by Frederick Cohn, translated by Charles S. Dolley, Rochester, N. Y.

Bacteria, - their relations to plant culture, by Thomas Taylor, Washington, D. C.

These two pamphlets are very timely in view of the recent discoveries of Prof. Burrill, in connection with "Fire-Blight" in the Pear and the Yellows in the Peach. As our readers know Bacterium is the smallest of all vegetable organisms. They are always present in ferments and putrefactions; and they abound in the circulatory vessels of human beings, and animals suffering from epidemic and contagious disorders. Prof. Burrill found them in great quantity in the early stages of the Pear and Peach diseases, and matter taken from a diseased part induced disease in healthy places, yet none of Cohn's experiments prove that Bacteria ever interfere with life. Their mission seems to be to rot up rapidly organisms from which life has departed. They are the scavengers of nature.

Yet it has to be explained why they are in such immense numbers in sick people, and why the virus in which they abound carry the diseases to the Pear and Peach tree. We have no doubt these seeming 'contradictions will yet be reconciled. It will not do to say the observations contradict each other, and so both cannot be true. There is no doubt of the correctness of the observations on both sides, and it will be the province of future researches to reconcile them.