318 Chronicles of Science. | April, 
collections of dried wild plants of each separate county, classified ac- 
cording to the natural system. 2. Three gold medals for the best 
three of all the collections out of all the several county collections. 
These collections must be arranged according to a natural method, and 
be accompanied by a list arranged according to the same method, with 
the species numbered. ‘The collector is to follow some work on 
British botany, such as Babington, Hooker and Arnott, or Bentham, 
stating the work adopted. The collections must be delivered on or 
before 81st December, 1864, to the Secretary of the Royal Horticul- 
tural Society. Further, the Society will present a gold medal to every 
exhibitor of a new species of plant found growing in the United King- 
dom. We need hardly point out that these regulations offer an excel- 
lent opportunity to the members of the various Field Naturalists’ Clubs 
which are scattered throughout the kingdom, and we anticipate that 
the stimulus thus publicly offered by the Royal Horticultural Society 
will be productive of the most beneficial results. 
At the January sitting of the Academy of Sciences of Vienna, M. 
Ettingshausen exhibited a work about to be published under the title 
of ‘ Photographic Album of the Flora of Austria, being at the same 
time a Manual of Botany.’ This is the first time that the photogra- 
phic reproduction of vegetables has been attempted as a new and im- 
portant means of botanical instruction. Hitherto it has been found 
impossible to obtain good photographs of plants, the images being black 
simple sketches without shade, on account of the green colour of the 
objects. Last year, the author, in giving an account of the recent 
progress of what he terms autophysiotypie, communicated to the 
Academy that at the Imperial Printing Office they had been able not 
only to obtain good photographs of plants, but also to engrave them 
so as to reproduce them by printing. The work above alluded to is 
the realization of this beautiful method. It embraces a complete 
selection of characteristic species of all the families of the Austrian 
flora, and interspersed with the text are the photographic portraits of 
hundreds of plants, just in the manner of woodcuts. M. Ettingshausen 
has also presented a memoir on the nervation of ferns, illustrated by 
the process of autophysiotypie. 
Mr. J. Hill of Cambridge, Mass., gives an account of some obser- 
vations upon the compass plant (Silphium laciniatum) which he found 
growing wild near Chicago, last autumn. The field had once been 
ploughed, and sowed with Timothy grass, and there was a grove a few 
rods to the east. Notwithstanding these unfavourable circumstances, 
he took a rough measurement of thirty plants, without selection, as 
follows :—Holding a card over each plant with its edge parallel to the 
central line of his own shadow, he marked upon the card a short 
line parallel to each leaf of the plant. Measuring afterwards the angle 
which each mark made with the edge of the card, and subtracting from 
each angle the azimuth of the sun for the estimated central time of ob- 
servation, he obtained the following results. Only one plant, bearing 
four old leaves, gave an average angle with the meridian of more than 
34° Their mean was 18° W. The remaining twenty-nine plants 
