404 BOTANICAL GAZETTE [MAY 
subject, from which it is evident that the greatest knowledge has come through 
dental studies. It has long been known that fungi, algze, and lichens can 
corrode or bore into rock, bone, or shell, and it has been assumed that they 
did this by excreting at the growing tip an acid which dissolved the calcare- 
Seems to appear first in Lind’s work. By adopting careful antiseptic precau- 
tions, he proves that a fungus may penetrate marble, chalk, eggshell, or 
bone plates, 0.07 to 0.2™™ in thickness, in eight or ten days. To do this there 
must be a chemotactic stimulus, usually furnished by some organic or inor- 
ganic food material that is needed by the plant. The stimulus seems useful 
to cause the acid-forminy surface to be pressed close to the rock in order to 
secure a sharply localized action. Microscopic examination shows that the 
fungus may pass directly through crystals. From a study of the action of 
oxalic and carbonic acids, the author concludes that the latter is pri- 
marily responsible for the etching, though oxalic acid may be accessory, 
especially in the presence of sodium chlorid which may afford hydrochloric 
acid by combination. The greater prevalence of such perforations 1 
marine than in fresh water shells is thereby explained.— F. L. STEVENS. 
ITEMS OF TAXONOMIC INTEREST are as follows: In Bulletin of the 
Torrey Botanical Club 26: 63-71. 1899) CHARLES H. PEcK has described 
twenty new species of fleshy fungii— EL1zaBETH G. BRITTON (did. 79-8!) 
Scattered genera. —K. M. WieGaAnp (zdid. 135-137) has described some 
species from Washington, and also (157-171) has published a bey 
of Listera, including twelve species, seven of them North American, two © 
which are new.—In Pitfonia (4: 25-52. 1899) E. L. GREENE publishes 
twenty seven new species in miscellaneous genera, the largest iene siete 
added to Sisyrinchium (5) and Silphium (4) ; discusses chronologically €at y 
specific types in Chameecrista as distinct from Cassia, discovers some twenty 
three, and transfers them from Cassia to Chamecrista; brings up certal? 
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