89 
but takes place later. The paraphyses and asci are always formed 
on the under side of the thallus, so that the young apothecia at 
first face the substratum ; their position is subsequently reversed by 
a strong curving of the fertile layer. We have therefore in these 
lichens phenomena of apogamy, similar to those that have been 
observed in the Ascomycetes. — Jour, Eo}\ Microscope Soc. ' 
The Coloring Matter of Flowers and Fruits, — In an interesting 
communication on the subject of coloring matters in flowers and 
fruits, contributed to a society at Wurzburg [Gard, Chron.^ June 20th, 
p. 794), Dr. A. Hansen gives reasons for supposing that a relatively 
small number of pigments suffices for the production of the apparently 
endless variety of tints. Taking flowers in the first instance, and 
setting aside chlorophyll green as being rarely met with in them, he 
recognizes three groups of colors, the yellows, the reds, and the blues 
and violets. "White is due merely to the reflection of light through 
colorless tissues containing air, and blacks are attributed io a con- 
centration of violet pigments. The yellow pigments are mostly in 
combination with plasmatic substances, whilst the reds and blues and 
violets are generally found in the cell-sap. The yellow of flowers is 
said to form an inslouble compound with fatty matters, which it is 
thought might explain the comparative permanence of that color in 
plants. The pigments of different yellow flowers have been found 
to agree with each other so closely in respect to their spectra as to 
point to identity, and Dr. Hansen obtained by saponification with 
soda, and extraction with light petroleum spirit, a crystalline yellow 
pigment which corresponded in its behavior to the "lipochrome *' 
obtained by Krukenberg from the animal kingdom. Orange is due 
to a denser deposit of the yellow pigment, the color in orange rind 
•being referrible to the same substance as that in the petals of Ranun- 
culus repens. The pigment in yellow dahlias and lemon rind, how- 
ever, behaves differently, both chemically and spectroscopically; it is 
soluble in water and seems to be very similar io the pigment of 
^thalium Septictim^ the yellow fungus or mould of rotten wood. The 
reds of flowers Dn Hansen reduces to a single pigment; the descrip- 
tion of which, so far as it goes, appears to correspond to that given 
some years since by Mr. Harold Senier of a coloring matter isolated 
by him from the petals of Rosa Gallica. The varying intensity of 
the colors of roses, carnations and p?eonies, it is thought might be 
due to the presence of acids, which, according to Mr. Senier, would 
deepen the shade of the red coloring matter, whilst the scarlets and 
brick-reds of poppies, scarlet lilies, and dog-rose hips are attrib- 
uted to the modifying influence of some yellow pigment (lipochrome) 
present. ^The blue and violet pigments, Dr. Hansen looks upon 
as derivatives from the red, and in support of this view it is 
pointed out that certain flowers pass from red to blue or violet. 
It is also known that the paeony-red is changed to violet by salts of 
iron or sodium phosphate, whilst gardeners produce blue hydrangeas 
by adding iron to the soil. As to fruit and leaves, the change of 
color which takes place in the autumn is accounted for by the decora- 
position of chlorophyll, with the formation of new pigments, or the 
unmasking of yellow (lipochrome) previously dominated by the 
