SCIENTIFIC SUMMARY. 
199 
These bundles originate in connection with those which pass into the ovarian 
walls, and which correspond to the margins of the five carpels ; passing into 
the placenta they ramify, and the ovules are borne at their terminations. 
He then examined the outer floral whorls in cases where their parts produce 
an accessory piece or appendage on the inner face or at its base, such as the 
petals of Ranunculus, of Oleander, the crown of the perianth of Narcissus, 
the stamens of Cobcea , &c. In all these the vascular bundles of the internal 
appendage or crown equally have their liber-cells facing toward the axis of 
the flower, their spiral vessels turned from it. Van Tieghem therefore con- 
cludes that, as these accessory pieces are appendages or deduplications of the 
petals, stamens, &c., so the free central or basilar placenta consists of in- 
ternal appendages or deduplications of the carpels ; also that each ovule 
answers to the lobe of leaf. 
Whence proceed the Flowers of the Larch ? — Mr. Thomas Meehan, who has 
a paper on this subject in the “ Proceedings of the Academy of Philadelphia,” 
says that at the flowering time of the larch the male and female flowers 
proceed from the termination of the spurs — not merely u of the preceding 
year,” according to Gray’s “ Manual,” but in some cases of many preceding 
years, a the sterile from leafless buds, the fertile mostly with leaves below ” 
(Gray’s “Manual,” 5th ed., p. 472). Why have the female flowers leaves 
under them, and the male none P Comparing the male and the female cat- 
hins, we see why. The scales of the male are formed out of the leaves 
which become fully formed in the female one. The pair of anther cells are 
thus simply on the back of a transformed leaf, just as we find the spore- 
cases of ferns borne in the same way. The weaker organisation which he 
has shown in his paper and communications on sex, permits no further 
development here. But in the case of the female flower, the leaf maintains 
a separate organisation all through the catkin or cone j and, as shown in his 
paper on the “ Stipules of Magnolia,” the midrib of the leaf shortens, and, 
assuming a stipular character, increases in width, until we have the purple 
bractea so well known in Larix. As soon as these bractea have been arrested 
in their development, the carpellary scales, which answer to the phylloidal 
fascicles of Finns, commence their growth in most species of larch, finally 
equalling the bracts in length. 
The Various Species of Yeast which attach Fruits. — These have been in- 
vestigated by M. le Dr. Engel, who has written a short memoir on them, 
that has been presented to the French Academy (“ Comptes Rendus,” Feb- 
ruary 12, 1872) by M. Pasteur. He formulates his conclusions thus. (1) 
He has found a rapid, easy, and certain way of making alcoholic ferments 
fructify. He has found by this means two very distinct species. (2) 
He has examined about twenty different species of fruits in order to 
study the ferments. Generally they (ferments) are found on the surface, 
and in this state they remain inactive. However, when any part of 
the skin of the fruit is broken, they make their way, and then they 
become fully developed, and undergo their development fully. (3) An 
examination of this kind has proved to him that the fermentation of bread 
is totally different from that of beer. (4) He has never been able to cause 
the fungus to germinate when the fruit contains little or no sugar, but in 
those which contain sugar it germinates rapidly. (5) The two genera to 
