464. M.E. Boissier on new Facts in Botanical Geography. 
of 10-12 millims., and long been furnished with the wing-like 
cephalic ridges (which make their appearance when it is about 
6 millims. in length). 
Unfortunately this interesting discovery has given us no 
definite information as to the mode of introduction. No re- 
mains of animal matters could be detected in the contents of the 
stomach; but who can tell how long the embryos had already 
been in the stomach? A second young cat, which had eaten 
the mucous membrane of the stomach of the former, together 
with the parasites still living in it, showed the worms on the 
following day likewise in the stomach, and hardly perceptibly 
altered from their previous condition. 
It appears clear to me, however, that it is not by any of the 
larger animals that the embryos of Ascarides are conveyed into 
the intestine of therr definitive bearer. As things remain from 
the preceding observations, we need for the completion of our 
knowledge of the life-history of the Ascarides only a single ele- 
ment. May we soon succeed in filling up this gap, and thus 
bring the commonest of the human Entozoa completely within 
the domain of science. 
L.—WNote on some new Facts in Botanical Geography. 
By Epmonp Botssizr*. 
By generalizing observations which are nearly always incom- 
plete (as we are still but imperfectly acquainted with most 
floras), botanists, ascertaining the predominance in some parti- 
cwlar botanical region of certain families or genera, hurry some- 
times, and prematurely, to the conclusion that this region is their 
exclusive habitat. Nevertheless new facts come from time to 
time to show us that there is nothing absolute in the laws which 
have governed the present distribution of plants upon the sur- 
face of the globe; and some interest attaches to the registration 
of these facts and to the combination in this manner of the 
materials which will perhaps hereafter assist in explaining the 
formation of the different floras. 
There have recently been discovered in Europe and Asia Minor 
some species which are particularly interesting, inasmuch as 
their congeners inhabit very distant regions. The first of these 
is a Dioscorea. The Dioscoree are dicecious monocotyledonous 
plants with generally a twisting and climbing stem. Their root 
is a tuber; and that of some species is employed as food, under 
the name of Yam. The genus Dioscorea is very numerous in 
* From the ‘ Bibliotheque Universelle,’? March 25, 1866, Archives des 
Sciences, pp. 255-260. 
