NOTES AND ABSTRACTS. 



347 



and they are easily carried from one country to another on their host 

 plants. This bulletin contains a description of many species and 

 some very remarkable drawings. — V. G. J. 



Seed, Germination of, as atffected by Sulphuric Acid Treatment. 



By H. H. Love and C. Leighty {U.S.A. Exp. Stn., Cornell, 

 Bull, 312, March 1912). — In this bulletin the value of concentrated 

 sulphuric acid sp.g. 1.84, for immersing hard seed to assist germina- 

 tion, is discussed. 



The treatment varied with an immersion of 30 to 180 minutes, 

 and the germination was increased up to 50 per cent. 



Certain weed seeds were destroyed by the process, as were some of 

 the fungoid diseases. — C. P. C. 



Shading of Tobacco Plants, Effect of. By Heinrich Hassel- 

 bring {Bot. Gaz. April 1914, pp. 257-286 ; i fig.). — ^The author's 

 experiments were intended to show the effect of cheese-cloth shading 

 on the transpiration and assimilation of the tobacco plant in Western 

 Cuba. 



He found that the total light was about one-third less in the shade 

 on bright days, but there was very little difference in diffuse hght 

 (Wynne exposure-meter). The cheese-cloth tents show a very slight 

 tendency to retain heat. The relative humidity is higher inside the 

 tents, especially towards the end of the season, and the rate of evapora- 

 tion is constantly less. There is also a reduction of air current. 



Transpiration is therefore diminished. The author found that it 

 was 30 per cent, greater in the open or sun plants, and per unit area 

 of leaf surface nearly twice as great when compared with shaded 

 plants. j 



The total plant substance is not diminished, but the leaves of the 

 shaded plants have a much greater total area than those of plants 

 grown in the open. \ 



Relatively less material is deposited in the leaves and more in the 

 stems of the shade plants. 



Cheese-cloth shading in Cuba, where tobacco is grown by irrigation, 

 results in a saving of water and a reduction of the loss of water from 

 the soil. — G. F. S. E. 



Sixteenth-Century Gardens in Germany. By K. Wein (Beih, 

 Bot. Cent. xxxi. Abt. 2, Heft 3, pp. 463-555). — The author gives 

 a long list of the plants in cultivation in German gardens about the 

 year 1561. This is obtained chiefly from Conrad Gesner's "Horti 

 Germaniae,'' who quotes the different gardens (chiefly belonging to 

 apothecaries and doctors) where the plants were grown. Coldenberg's 

 garden in Antwerp contained many Spanish plants. 



The list here given by Herr Wein should be of great importance 

 to those interested in the story of gardens generally, and it is perhaps 

 worth while to give a selection of some of the more interesting species 

 mentioned. 



A very large proportion of common or garden plants were already 



