of the Kingdom of Algiers. 435 
plants, and of pointing out the most remarkable species which 
occur in Algeria, but I find that it would only draw out this 
paper to an immeasurable length. 
I cannot however pass over a new species of Stapelia, named 
by Decaisne Boucerosia Munbyana, and discovered by me in the 
neighbourhood of Oran, interesting in a geographical point of 
view ; it is well known that the great seat of Stapelias (which is 
a most distinct and perfectly natural genus) is at the Cape of 
Good Hope, and until lately only one species occurred in Europe 
as a representative of this genus; I speak of Stapelia europea, 
which is found in Sicily and the southern coast of Spain. The 
discovery of an allied species on an intermediate point 1s I con- 
ceive very interesting, and will in all probability form the second 
link in a chain which will connect the humble Stapelia europea 
with the remarkable Cape species. 
I shall conclude this paper by noticing a lichen called L, escu- 
lentus, and which agrees, at least more nearly than any other 
substance hitherto discovered, with the description of the Manna 
on which the Israelites fed during their wanderings in the desert. 
This lichen is found on the sand of the desert, which it covers 
in some parts, and grows during the night, as do many mush- 
rooms. The French soldiers during an expedition towards the 
south of Constantine actually subsisted upon it for some days, 
cooking it in various ways, and even making it into bread. I do 
not pretend to explain the miraculous portions of the history of 
the Manna, but it is very probable that if gathered when alive or 
in a soft state, it would im a very short time ferment if placed in 
a heap, and from the rapid development of animal life in that 
warm climate, “breed worms and stink” in a very few hours. 
Neither would I attempt to explain the double quantity gathered 
on the sixth day. The description given by Moses is this : “Upon 
the face of the wilderness there lay a small round thing, as small 
as hoar-frost on the ground ;” and again, “ it was like coriander 
seed, white ; and the taste of it was like wafers made with honey.” 
There are a few characters in this account of it which disagree 
with the substance I present to you, yet the discovery of a sub- 
stance springing up in the short space of a night on the surface 
of the sandy desert, and that substance capable of sustaining 
human life, is, to say the least, a remarkable fact, and one well 
worthy the examination and researches of botanists. 
