Long to the sources of the St Peter's river. This task he undertook with that diffidence which signalized his real merit, expressing his regret that the unavoidable absence of Mr. Nuttall from the country should have prevented him from executing this undertaking, agreeably to previous arrangement, and passing on that gentleman a high and delicate eulogium; how richly merited, this Academy needs not to be informed.
Near the close of the same year, he also communicated to the Lyceum of Natural History at New York, a valuable paper, containing instructions for determining the American species of the genus Carex, a work, which, though less imposing in appearance, must doubtless have cost more intense application, and more exact powers of discriminating between specific characters, than would have sufficed for the description of many new species of plants.
In 1824 Mr. Schweinitz communicated to the American Journal of Science a short paper on the rarer plants of Easton, Pa., almost all of which, he remarks, are principally met with on the shady rocks up the Delaware, or at the mouth of the Lehigh.
In the same year appeared his Monograph of North American Carices. Being about to embark a third time for Europe, this paper, together with a large collection of the specimens from which it had been prepared, was placed in the hands of his friend, Dr. Torrey, with a desire that it might be communicated to the Lyceum of Natural History, and giving him full liberty to use his discretion in the additions or altera-