26 
THE AMERICAN BOTANIST. 
backward as in figure 2, after which make a third fold at right 
angles to the second (on the dotted lines in figure 2) push the 
free end under the first fold (fig. 3) and the packet is complete. 
This packet has the merit of being instantly made, when desir- 
ed, wherever a piece of paper can be procured and if properly con- 
structed will hold without spilling flour, dust or the finest seeds. 
It is worth the while of anyone who does not know how, to get a 
sheet of paper and learn to make this packet. There are hundreds 
of occasions when the knowledge will be useful~W. N. C. 
ORIGIN OF SPECIES BY MUTATION. 
Three kinds of evening primroses occur in Holland, all three 
introduced from America about a century ago, but since escaped 
from cultivation. The youngest of the three or rather the one 
most recently introduced, and at the same time the most rare, is the 
large-flowered evening primrose, described at the beginning ot 
the nineteenth century by Lamarck, and named after him Oeno- 
thera Lamarckiana. It is a beautiftil, freely branching plant, of- 
ten attaining a height of five feet or more. The branches are 
placed at a sharp angle with the erect stem and in their turn bear 
numerous side branches. Nearly all branches and side branches 
are crowned with flowers, which, because of their size and bright 
yellow color, attract immediatq attention, even from a distance. 
The flowers, as the name indicates, open towards evening, shortly 
before sunset, and this so suddenly that it seems as if a magic 
wand had touched the land and covered it with a golden sheet. 
Bumble bees and moths, especially those of Plusia gamma and of 
Agrofis scgetum, are the principal visitors. During the hot 
weather the flowering period is limited to the evening hours. In 
daytime often nothing is to be seen but faded and half-faded flow- 
ers and closed buds. Each flower bears a long style with four or 
more stigmas, which protrude at some distance above the eight 
anthers, and would therefore, as a rule, not be fertilized without 
the help of insects. When the flowers, including their apparent 
stem, the calyx tube, drop off, there remains behind a perigymous 
ovary, which finally becomes a capsule. At first green, it be- 
comes brown on ripening and finally opens with four val- 
