NOTES AND ABSTRACTS. 



28l 



known to have been spread through manure of stock fed with diseased 

 tubers. 



Implements used on infected land should be thoroughly clean. 



D. M. C. 



Dombeya Mastersii. By W. T. (Garden, p. 3, Jan., 1912). — The 

 genus comprises some thirty species of handsome evergreen shrubs or 

 small trees, natives of Africa or the Mascarene Islands, and should be 

 more generally cultivated. D. Mastersii is worth attention. There 

 is a fine specimen planted out in the Temperate House at Kew. The 

 fragrant pearly-white flowers, about 1 inch in diameter, are produced 

 in axillary corymbs near the end of the loosely spreading branches ; 

 the leaves, heart-shaped and velvety, are 3 to 6 inches long and 2 to 

 5 inches wide. It commences to bloom in October, and continues 

 through winter and early spring. Propagation by cuttings in March 

 and April. — H. R. D. 



Douglas Fir, Fire-killed, Damage to the Wood of : and Methods 

 of Preventing Losses in Western Washington and Oregon. By A. D. 



Hopkins (U.S.A. Dep. Agr., Bur. Entom., Circ. 159 ; July 27, 

 1912). — Wood-boring insects play sad havoc amongst the trees of 

 Douglas Fir that have been killed by fire. The general methods to 

 avoid damage to the trees are prompt utilization of the timber 

 within about a month after the fire, removing the bark and placing 

 the logs in water. — A. D. W. 



Douglas Fir, Fire-killed : A Study of its Rate of Deterioration, 

 Usability, and Strength. By Joseph Burke Knapp (U.S.A. Dep. 

 Agr., For. Serv., Bull. 112 ; Sept. 30, 1912). — As regards the value 

 of timber that has been subjected to forest fires, the tests indicate 

 that the sound wood from fire-killed Douglas Fir may safely be used 

 for constructive purposes, and that its merits are nearly, if not quite, 

 equal to those of material from green growing trees. — A. D. W. 



Echium Wildpretii and Allied Species. By G. V. Perez (Gard. 

 Chron., p. 19 ; Jan. 11, 1913 ; 4 figs.). — Suggestion that useful crosses 

 might be raised with our native E. vulgare. — E. A. B. 



Ecology of Delaware Coast. By Laetitia M. Snow (Bot. Gaz., 

 PP- 45-55 \ J an - I 9 I 3 ', with 6 figures). — The author revisited this 

 district after an interval of ten years and notes the progress of coast 

 erosion and the differences in vegetation during this period. — G. F. S. E. 



Enzymes, Chlorides and Action of. By L. A. Hawkins (Bot. Gaz., 

 pp. 265-285 ; April 1913). — The author describes the effect of sodium, 

 potassium, magnesium, iron and copper chlorides in various solutions 

 (singly and combined) on the action of malt diastase on starch extract. 

 Much variation was found. More or less pronounced acceleration of 



