512 The Botanical Gazette. [September, 
the grooves are but the stretching out of the pulvini; the sheath in 
Cylindropuntia is formed from a coalescence of hairs; species of 
Opuntia, Cereus, Mamillaria possess honey-secreting structures which 
are always either ordinary or metamorphosed spines; the transverse 
rings shown by many thorns are due to alternating zones of air-con- 
taining and air-free tissue; the bundle systems of all genera are modi- 
fications of the typical system seen in Opuntia. By using a combina- 
tion of vegetative and floral characters the generic relationships are 
indicated by the usual phylogenetic diagram. It is very valuable for 
our systematic work to have such careful morphological studies made, 
as too much of our work is based upon a very superficial morphology. 
Tue JouRNAL oF Myco.ocy appears at such long intervals that a 
new number is especially noteworthy. The last one is no. 4, the 
final one of volume seven. It contains 146 pages of printed matter 
and six plates. Forty-eight pages, however, are devoted to an index 
of volume seven, and thirty-two to the continuation of the general 
bibliographical index of mycological literature. The latter is admira- 
bly done, and if it could only be reissued on cards, would be invalua- 
The number is largely devoted to fungicides, and methods and 
results of their application. A fungus (Aschersonia tahitensis Mont.}, 
new to the country, is reported by H. J. Webber as being of possible 
economic importance in Florida in checking the abundance of such 
scale insects on orange and other citrous fruits as secrete honeydew, and 
thus harbor the sooty mold, a serious fungous disease. Interesting © 
field notes for 1892 by Erwin F. Smith, include especially a notice of 
root tumors of the peach. Nine articles of foreign literature are Te- 
viewed. < 
are especially interesting parts of the essay. The thorough manner 
in which the subject is handled in all its bearings makes the work one 
of the most important contributions relating to fungicides issued up 
to the present time. ! 3 
a ee tc aC a 
1 Farrcuitp, D. G.:—Bordeaux mixture as a fungicide. Bulletin No. 6 of 
the Division of Vegetable Pathology. 8vo. pp. 55 Washington, Government 
Printing Office. 1894. 
