152 BOTANICAL GAZETTE [FEBRUARY 
already and previously been clearly made by PENHALLOW. The author also 
attempts to separate the woods of the Podocarpez from those of the Cupressineae 
in the larger sense, on the basis of the structure of the pits in the ray-cells. The 
success of this distinction may be judged from the fact that it results in putting 
Sciadopitys with the Podocarpéae. Pityoxylon of Kraus is broken up by this 
writer into two genera, Piceoxylon and Pinusoxylon. The latter genus repre- 
sents the wood of Pinus, and seems somewhat unfortunate, since it is doubtful if 
the mesozoic pines had the wood structure which is found as characteristic of 
that genus in Tertiary and modern times. There are also disquisitious on spiral 
_Striation in the wood of the nosperms and on the value of annual woody 
rings as diagnostic of geologic formations. The work closes with two tables for 
the determination respectively of living and fossil gymnospermous woods. There 
is likewise an index and an alphabetical list of the living woods investigated by 
the author.—E. C. JEFFREY 
Injury by smoke.—F requent controversies and law suits, arising from damage 
to agricultural crops by the smoke produced by manufacturing establishments 
in Germany, have made the recognition of this form of injury extremely impor- 
tant. In order to furnish a basis for distinguishing smoke-injury from injuries 
due to other factors, SorAvER'S has made a comparative anatomical study of 
various kinds of injury commonly occurring in the more important grains, oats, 
wheat, and barley. The paper contains detailed comparative descriptions of 
changes in the cell walls and cell contents which cannot be severally noted here. 
The general plan followed in each case is represented by the following heads: 
e behavior of the normal plant in its gradual, natural dissolution; abnormali- 
ties in smoke-free regions; the phenomena in plants injured by chlorin and by 
hydrochloric acid fumes; experimental tests of the influence of hydrochloric 
acid fumes; phenomena confused with smoke injuries. In natural death the 
cells lose a large part of their contents and finally (except the epidermal cells) 
collapse completely. This process first involves the tip and edges of the leaves. 
In cases of death resulting from other causes, as drought, the cells do not collapse 
so completely, since the contents are not fully resorbed. In injuries due to acid 
fumes from smoke, the contents of the mesophyll cells contract into an irregular 
greenish lump, while the cell walls partially collapse. 
The most striking feature about this form of injury is the collapse of the 
epidermal cells. The accompanying changes of the cell contents and cell walls 
in these and in many other forms of i injury are minutely described. The recogni- 
tion of smoke injury in general is based on the fact that the cells, dying rapidly, 
collapse partially without being emptied of their contents, the epidermal cells 
showing the same phenomena. The author continually emphasizes the fact, 
however, that no clearly defined symptoms for the absolute and certain recogni- 
tion of smoke injury can be given, but that in all cases a comparative study of 
. 13 SORAUER, P., Beitrag zur anatomischen Analyse rauchbeschadigter Pflanzen. 
Landw. Jahrb. 33:585-664. pl. 15-18. 1904. 
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