280 BOTANICAL GAZETTE [ApRin 
this species have been collected in Florida by Dr. Chapman, in Dele 
ware by Mr. Canby, and in eastern North Carolina by the Biltmore 
Herbarium. All of the material, except possibly that from Delaware, 
compares favorably with Mr. Kearney’s specimens collected in Cocke 
county, Tennessee, in habit, lobing of the vexillum and peculiarities 
of loment. In the plants from Delaware the vexillum is not con 
stantly lobed, differing in this respect, indeed, on the same individual. 
—C.D. BeabLe, Biltmore Herbarium. 
THE GUM OF CANNA. 
WHEN a freshly cut tuber of Canna is exposed to the ait, ee 
may be observed upon the cut surface, after some hours, the formation 
of small colorless or pale yellow drops, which stiffen rapidly in el oi 
From these there finally develop spherical masses of no mean sit 
Their color varies from very pale yellow to brown or bottle-greet. . 
fractured they show a glistening and conchoidal appearance. aed 
substance has the character of a gum. Itis insoluble in yore 
after long boiling, and it swells up in precisely the same way as do 
gums of the cherry and apple. 
When heated upon a platinum knife this gum of Canna sw 
chars, and then burns with a smoky flame, leaving considerable ti 
white and light ash. This ash contains calcium carbonate, magne 
iron, potassium, and phosphoric and hydrochloric acids. oo 
For the study of the method of the formation of this eee : — 7 
found convenient to use rootstocks which had first been eae : 
strong alcohol. Sections were examined, either at in ai ced DF 
made, or after having been subjected to a double stain pr strat of 
Successive immersions in a hydro-alcoholic solution of red : s The 
Cassella, and a similar solution of acid green JEEE (Poirrier). 
washings were made in water containing alcohol, and the 
mounted in carefully prepared neutral glycerine. bly on account 
Staining with haematoxylin gave poor results, probal y fthe gua : 
of the resistance offered to its diffusion by the insolubility : to assig? 
Upon first examination of the preparations one 1s aie 
SI prepared these solutions according to the following formule: 
: i ae 
gm 9 er) % 
Rouge de Cassella 0.25 Acid green JEEE (Poirr! ) no 
Alcohol at 90% 20.008" Alcohol at 90% 7.00 
Distilled water 30.008™ Distilled water 
