Dr. Marsh’s book cannot fail to promote the practical study of histology wherever the English language is spoken, and under ordinary circumstances the students of this country might have been left to the use of the London edition. But a careful reading showed that one or two points which are perfectly clear to British readers might be a source of doubt and difficulty to students on this side. At the present day in this country histology is a favorite study with very many private students who have no access to teachers or large libraries, and for the purpose of smoothing their path we have added such information as was obviously desirable. In the hope that these additions will prove of value, we submit the book to American readers.

New York, January, 1879.