SCIENTIFIC SUMMARY. 
85 
paper in the above journal^ by Dr. Masters. This extends over sevent^^ 
pageS; is illustrated by two plates drawn by Fitch, and is an important 
monograph in continuation of researches already published in the Linnean 
Journal by the author. 
How Fern spores are scattered . — An American botanist, Dr. W. L. Wells, 
has been studying the phenomena of rupture of the sporangium of Foly- 
podium vulgare. Under the microscope the sporangium could be seen to 
open at a point near its stem, and the opening grew very slowly larger until 
the continuation of the stem which previously encircled the sporangium was 
nearly straight. It then suddenly shut with a jerk, scattering the spores in 
every direction, and generally sending the sporangium itself out of focus. 
In the cases in which it was not thrown entirely out of focus, the same 
operation could be seen to be repeated two or three times. In no case were 
any spores scattered during the opening, which always took place very slowly. 
Dicecism in Epigcea repens . — In the Proc. of the Academy of Nat. Science 
of Philadelphia, Mr. Thomas Meehan speculates on the fact which he has 
observed of the practical dicecism of Epigaea repens, the hermaphrodite 
flowers proving sterile. There would seem, he says, to be two distinct 
principles in relation to form going along together with the life of a species. 
The tendency of the one force is to preserve the existing form ; the other 
to modify it, and extend it to newer channels. The first we represent by 
the term inheritance.^ the other we understand as variation. Inheritance 
struggles to have the plant fertilise itself with its own pollen, while the 
effects of variation are towards an intermixture of races or even neighbour- 
ing individuals, rather than with members of the one brood or family. May 
it not be possible that at some time in their past hist Dry all species of plants 
have been hermaphrodite? that dicecism is a later triumph of variation, 
its final victory in the struggle with inheritance ? There are some 
difficulties in the way of such a theory, as there are with most of these 
theories ; but it seems clear from this case of Fpigcea that cultivation has 
not so much to do with changes as it gets credit for, and we may readily 
believe that independently of external circumstances there is a period of 
youth and a period of old age in form as well as in substance^ and that w-e 
may therefore look for a continual creation of new forms by a process of 
vital development, just as rationally as for the continued succession of new 
individuals. 
Monoecismin Sugula campestris. — The same observer, Mr. Thomas Meehan, 
has determined the practical moncecism of Sugula campestris. The three 
stigmas are produced through the apex of the flower-bud some days before 
the sepals open and expose the anthers. The stigmas are fertilised by the 
pollen of other flowers and wither away before their own flowers open. 
CHEMISTRY. 
Vegetable Tar as a Bye-Stuff. — M. Lefort proposes to use vegetable tar 
for dyeing purposes. It contains on an average about one per cent, of 
oxyphenic acid, which it readily gives up to water, forming thereby a liquid 
