In the Revue Scientifique for the 13th of September, 1879, Professor Carl Vogt published a remarkable article on the Archæopteryx. This Memoir being in a periodical that would not come under the notice of all readers in this country, an excellent translation of the paper was published in the Ibis. It is difficult, if not indeed somewhat unhandsome, to criticize Carl Vogt's contribution; seeing that it makes known the famous second skeleton of Archæopteryx, which had long evaded all efforts to learn its characters. The present writer followed it from Solenhofen, in its migrations over Germany, only to find it guarded like a sacred mystery in the house of Otto Volger, in Frankfort. But while very difficult, from not having seen the specimen, for me to speak with any confidence on points of the anatomy of Archaopteryx in which Carl Vogt's conclusions may be open to discussion, it is much easier, and, indeed, almost a pleasant duty, to differ from him emphatically in the philosophical conclusions drawn from his study of the slab. And I here offer a few remarks, since the like have not been volunteered from any one more competent to speak on the subject, concerning reasons why naturalists should at least hold their judgment in suspense before adopting some of the learned Professor's new conclusions, and in the hope of elucidating the true nature of this singular fossil.