172 
Crategus Holmesii, Cissites microphyllus, Grewiopsis satiate 
Phyllites fraxineus and P. mimusopsoideus. 
Lobelia.—C G. Lloyd. (Drugs and Medicines N. A., ii, pp. 
IOI-106; one plate.) 
Descriptions are given of structure, history and medical 
properties of L. syphilitica and L. cardinalts. 
Milkweeds.—Joseph F. James. (Amer. Nat., xxi., pp. 605-615; 
nine figures.) 
A popular account of the structure of the flowers, the pollin- 
ation and economic relations of the Asclepiadez. 
Movement of Diatoms.—Cornelius Onderdonk. (The Microscope, 
May, 1887.) 
Although several theories have been proposed to account for 
the movement of diatoms, none have proved so satisfactory as to 
be generally accepted. This paper will be read with interest by 
those who have made the matter a subject of thought. Mr. 
Onderdonk’s theory is, briefly, as follows:—That living pro- 
toplasm is matter in rhythmic motion and dead protoplasm is ° 
matter at rest; that all living diatoms are encased in an envelope 
of protoplasm, and that it is the rhythmic action of this that 
causes the motion of the frustules. He calls attention to the fact 
that the force exerted is immediately on the surface of the diatom ; 
that this force is exerted over the surface from end to end of the 
diatom, and that the force is rhythmic.. He considers this 
rhythmic motion to be akin to the cyclosis which takes place in 
the interior of a cell. Geeks 
Nitrogenous Bodies in Plants—The Occurrence and Functions of 
Certain.—W. E. Stone. (Bot. Gazette, xii., pp. 123-130.) 
An interesting account of present knowledge of this subject. 
Origin of the Tomato from a Morphological Standpoint.—L. H. 
Bailey, Jr. (Amer. Nat., xii., pp, 573-576; one plate.) 
Reasoning from the results of an exhaustive study of twenty- 
five varieties of cultivated Tomatoes, Professor Bailey concludes 
that the “Cherry Tomato,” Lycopersicum cerasiforme, Dunal, is 
the original type from which all the others have been derived. 
Primer of Botany.—Mrs. A. A. Knight, Robinson Seminary, 
Exeter, Mass. (Ginn & Co., Boston, 1887.) ‘ 
The object of this little book is to present the essential points 
