1916] CURRENT LITERATURE 167 
grows out of the seed carrying the plumule and hypocotyl with it. The length 
of the tube varies in different species; and in M. horridus the elongated tube 
“absorbent hairs.” In emerging from the tube the hypocotyl breaks 
through at the base, and later the plumule pierces the side of the tube. Even- 
tually a hypocotyledonary tuber is formed, which may become very large. 
In M. horridus the interesting discovery was made that in connection with 
the growth of this tuber the cotyledonary tube splits into 6 separate parts, 
each of which contains a vascular strand.—J. M. C. 
An automatic transpiration scale——The extensive work of Briccs and 
SHANTZ” upon the water relations of plants in arid and semi-arid regions, and 
more particularly their water requirement measurements, has necessitated 
the construction and use of an automatic scale of 200 kg. capacity, page 
to 5 gm., in order to measure the transpiration of plants freely exposed to win 
and weather. Such a scale is described in a recent publication. te it steel 
tion balances, both of the step-by-step type, which includes the scale here 
described, and of the continuous record type.—Gro. D. FULLER. 
Field rot of potato tubers.—PRaATTI™ points out some interesting facts that 
he discovered in his studies of the potato rot situation in Idaho. “Stem end 
rot,” “field rot,” or “black rot” of potatoes of the round type, such as Rurals and 
Pearls, and jelly end rot of tubers of the Burbank group are induced by Fusarium 
icicola. The organism is active at temperatures above 50° C. and 
can therefore be controlled in storage. Field control of the black rot 
situation is difficult. Seed pieces afflicted with black rot bring about infection 
of the following potato crop, and, interestingly enough, virgin soils produce 
heavier infection than lands that have been put to crops.—G. K. K. Luyx. 
“ 
Recent work in embryology.—SovurcEs,* in continuing his embryological 
studies, has published an account of the Cruciferae, which traverses the classic 
work of HaNnsrern and Famrntzin. The figures are chiefly those of Lepidium 
sativum, although other species of Lepidium (L. campestre and L. Draba) and 
Cochlearia officinalis are included. 
22 Bor. Gaz. 56: 514-515. 1913. 
* Bricos, L. J., and SHanrz, H. L., An automatic transpiration scale of large 
capacity for use ie ees exposed plants, Jour. Agric. Research §:117-132. 
bls. g-11. figs. 18. 1915 
Pratt, O. A., A western field rot of the Irish potato tuber caused by Fusarium 
radicicola, Jour. Katie: Research, Dept. Agric. 6:297-309. pls. 34-37. 1916. 
* Soukcrs, M. R., Développement = prions chez les Cruciféres. Ann. Sci. 
Nat. Bot. 19:311~339. pls. 11-14. figs. 76. 1914 
