349 BOTANICAL GAZETTE [OCTOBER 
concentric bundles were produced in the proliferating pith. In these the 
phloem was always at the center of the bundle. Such bundles, the author 
points out, occur normally in the axes of the inflorescence of Ricinus and in the 
nodes. Superficial intumescences similar to those reported by VON SCHRENK’ 
were produced on cauliflower by exposure of the plants to vapors of ammonia 
and of acetic acid mixed with alcohol. 
e outgrowths here described all partake of the nature of intumescences 
frequently observed in plants. In some cases, indeed, as in the instance de- 
scribed of the complete filling of the pith cavity and the subsequent differentia- 
tion of a vascular ring, the outgrowth is excessive. This behavior leads the 
author to the belief that if the stimulus could be continually applied, one would 
have a condition resulting in the production of tissue masses not unlike those of 
crown galls. Since in his experiments the outgrowths also resulted from the 
presence of many substances not the product of parasites, the author is inclined 
not to attribute the effect to the specific chemical action of any compound, but 
seeks for an explanation in some property common to all the compounds regard- 
less of chemical composition. Such a common characteristic he finds in their 
osmotic action, to which, rather than to chemical sana gatecrey he — their 
effect. In this ection it is of interest to recall 
produced by Arxrinson,? Miss Douctas,? and STEINER” by ahi plants 
to conditions increasing water absorption and diminishing transpiration; and 
by Soraver, KiisteR, von ScHRENK, and others as a result of application of 
solutions. In the author’s own work the intumescences were mostly the result 
of injection of solutions, but in some instances they resulted from the injection 
of water. It is improbable that the osmotic disturbances induced by the appli- 
cation or injection of water are the same as those effected by the application 
or injection of solutions. The fact that the various disturbances produce 
responses differing only in degree would seem to indicate that the causes deter- 
mining the formation of intumescences have not yet been fully analyzed into 
their separate factors. It is not unlikely that different plants react differently 
in this respect. The experiments of STEINER would seem to indicate that such a 
possibility exists —H. HassELBRING. 
Taxonomic notes.—GarTeEs" has attacked the genus Polygonatum, which 
he says “‘has been in a very chaotic condition owing to the lumping of species, 
the transference of names, and the confusion of North American with European 
7 Rev. Bor. Gaz. 40:390. 1905. 
® Arxinson, G. F., Oedema of the tomato, Cornell Univ. Agric. Exp. Sta. Bull. 
53:77-108. 1893. 
9 DouGLAS, igh G. E., The formation of intumescences on the potato. Bot. 
1907. 
10 Rev. fem Get 402391. 1905. 
. -™%Gares, R. R., A revision of the —_ web a een in North America. Bull. 
Torr. Bot. Club 44: 117-126. pls. 4-6. 
