Recent Literature. 835 
spore, or oöspore of Phanerogams, is the single fertilized cell in the 
embryo-sac, which at once develops into the embryo, at which 
point Phanerogams pass into the resting stage, in this group called 
“the seed.” The sex-spore, since the fourth group, has become 
such an evanescent thing, so out of reach of common observa- 
tion, that very naturally it has been the common opinioņ that the 
comparatively permanent asexual spores are sex affairs. Sex- 
spores are directly formed by sex-union; while pollen-grains and 
embryo-sacs are never formed in any such way. Thus have I 
hastily traced one of the principal threads upon which our botan- 
ical facts are strung. And as one examines the subject in more of 
its details, he becomes irresistibly impressed with the idea that here 
is a great scheme of development, directed by laws of which we are 
beginning to catch glimpses, and by which the whole fabric of a 
great kingdom has been beautifully and continuously worked 
out, 
RECENT LITERATURE. 
THE GEOLOGICAL HISTORY OF PLANTS. By Sır J. WILLIAM 
petos, C.M.G., LID., F.R.S., etc. International Scientific 
s an unevenness of treatment corresponding to the imperfection 
higa e geological record in the region to which he has devoted his 
ith vegetable origin of the Laurentian graphite is defended 
yi great force, and the existence of a primordi flora contempo- 
taneous with Eozoon canadense is maintained. Most of the alleged — 
