CURRENT LITERATURE. 
Embryology of the Amentifere. 
A recent paper' upon this subject, by Miss Margaret Benson, con 
tains some remarkable results. Embryologists have long looked 
hopefully at the Amentiferze as a possible fruitful field for the dis- 
covery of certain homologies of the phanerogamic embryo-sac. ‘The 
results here recorded have been obtained from work that has been 
going on since 1891, in the botanical laboratory at Cambridge, at the 
suggestion of Professor Oliver. The material was difficult to obtain 
in the right stages and much time elapsed before satisfactory results 
could be obtained. The present paper is but preliminary and frag- 
mentary, but it contains results that deserve announcement. British 
forms of Fagus, Castanea, Quercus, Betula, Alnus, Corylus and Car- 
pinus are considered. A comparison is instituted with Treub’s re- 
sults with Casuarina, indicating the close affinity of that genus with 
the Amentiferee. Treub, it will be remembered, considered the 
chalazal entrance of the pollen-tube a fact of sufficient importance to 
Set off the chalazogams (represented by Casuarina) against all other 
phanerogams (porogams). It now seems that Alnus, Betula, Corylus 
and Carpinus are also chalazogams. ‘The adaptations to this chalazal 
entrance are well pointed out. Other striking similarities aré to be 
found in the development in the Amentifere of genuine “sporogen- 
Ous tissue” in the nucellus, several similar contiguous cell-strands, 
from which one or more embryo-sacs are developed; and in the prev- 
alence of ceca formed by the embryo-sac (tails of macrospores) 
which serve for the unimpeded pathway of the pollen-tube up the 
nucellus, as in Casuarina, or forage for the needs of the embryo, as In 
agus. It is a question for which of these purposes the caca were 
originally acquired. In Castanea, also, there is a somewhat incon- 
stant development of tracheids around the base of the embryo-sac, as 
in Casuarina, taken to suggest some ancestral organ. The remarkable 
branching and resting stage of the pollen-tube found in the group 1s 
also suggestive of Casuarina. No intimation as to the homologies of 
the antipodal cells or as to the nuclear fusion of the embryo-sac was 
obtained. The group is evidently one worthy of exhaustive study, 
and likely to bring us somewhat nearer the solution of the problem 
a8 to the genesis of phanerogams. 
ar >. MarGaret. Contributions to the embryology of the Amentiferz, 
- Reprint from Trans. Linn. Soc. II. 3: 409-424. 6 p/. 
