1900] CURRENT LITERATURE 373 
specimens judiciously selected. The treatment of the Rule is the 
most comprehensive in the selection of material and in its preparation. The 
author, by his careful discussion of the various methods in the preparation of 
material emphasizes what is too often neglected in general histological 
studies, particularly of the lower forms, the careful preparation of material 
for examination. Much of the histological work with classes is misleading 
and useless because the teacher fails to appreciate this point. The student 
who learns to make a proper use of the best methods early in his course will 
be well repaid when at a later period he begins more critical studies. A 
convenient list of formulae for reagents is placed at the end of the volume. 
The technique of the book is good, and the illustrations well selected, a 
few of them being photomicrographs of excellent preparations. The work is 
a most acceptable contribution to the growing list of laboratory manuals.— 
M. s 
MINOR NOTICES. 
JAMEs R. Gow‘ has published a preliminary list of the flowering plants 
of Adair county, Iowa. 
WILDEMAN and DurRAND’? have issued a further publication on the Congo 
flora. It consists of the first fascicle of an enumeration of plants collected by 
Alfred Dewévre in 1895-6 in the state of Congo, and contains from Ranun- 
culaceae through Leguminosae, with descriptions of new species. A notice of 
the previous series may be found in Bor. GAz. 31:70. 1901.—J. M. C 
UND® has published a monograph of the genus Sorbus, which 
further rehabilitates a Linnean genus long included in Pirus. The author 
recognizes 58 species, and discusses them in great detail, with the help of 
text illustrations of venation, pollen grains, etc. He also includes subspecies 
and hybrids. Some ten or twelve North American species are involved.— 
}.M,C. 
THE FIRST part of the second volume of Wiesner’s Rohstoffe des Pflanz- 
enreiches has just been issued.2 It contains part of the seventeenth section 
on woods, newly elaborated by Dr. Karl Wilhelm with the assistance of Dr. 
S. Zeisel, who contributes the chapter on the chemistry of wood. The struc- 
ture of woods and their physical and chemical qualities are described in 51 
pp., followed by a synopsis (go pp.) of the more important plants whose wood 
* Proc. Iowa Acad. Sci. 8: 1-8. 190 
7Annales du Musée du Congo. Botanique. III. Reliqaiae.. Deweytoame. 
Fasc. 1. Bruxelles, May, Igo!. 
oo der Gattung Sorbus. Kongl. Svenska Vetensk.-Acad. Handl. 
35 * 1-147. 
9 WEISNER, JULIUS: Die Rohstoffe des Pflanzenreiches. Versuch einer tech- 
nischen Rohstofflehre des Pflanzenreiches. Second ed.  Lieferung 6. : 
1-160. Leipzig: Wilhelm Engelmann, 1901. 5. 
