I910] CURRENT LITERATURE 397 
Bai 
4 
: 
_ cavities of Lycopodium and the parichnos of fossil genera.” In some cases the 
sporophylls are provided with more or less conspicuous dorsal outgrowths, 
which have been noted heretofore only in a casual way, but not definitely 
described. Four types of sporophyll are described: (1) with well developed 
dorsal flap extending freely downward and protecting the young sporangium 
immediately below it (as S. rupestris); (2) with no dorsal flap, the sporophyll 
being flat and the sporangium exposed (as 5. spinosa); (3) witha well developed 
dorsal projection which is not free but decurrent (as S. helvetica); and (4) a 
series in which the dorsal outgrowth is gradually reduced and lost, each sporo- 
phyll more and more sega, infolding the sporangium below (as S. flabel- 
lata to S. apus).—J. M. C. 
Morphology of Callitris—Saxton,% in continuing his studies of gym- 
Nosperms, has given an account of Callitris, an Australasian genus of about 
_ 4 dozen species. The one chiefly studied was C. verrucosa, but the results 
multinucleate. The archegonia occur in a single group of about 20, never at 
the apex of the gametophyte, but along the inner side of the pollen tube near 
its apex. If two pollen tubes are ener two such groups are organized. 
Proembryo completely fills the archegonium, the arrangement of cells 
being variable. More than one embryo is formed troat a proembryo, and the 
genera, but that they should constitute a separate tribe (Callitrineae) coordi- 
hate with Cupressineae is not so clear.—J. M. C. 
Structure of Mitrospermum.—Mrs. ARBER” has investigated the structure 
of the platyspermous seed described by WILLIAMSON in 1877 as Cardiocarpon 
Principal plane of the seed, probably continuing almost the whole length of the 
e€ nucellus seems to have been entirely free from the integument, and 
in one seed a tissue within the embryo sac was observed, consisting of “‘irregu- 
lar roundish cells,” which of course represent the female gametophyte. The 
oo ., 
»« “Saxton, W. T. Pe awe: to the life history of Callitris. Annals of Botany 
.. pls. - 15 461 
, On a structure of the paleozoic seed Mitrospermum com- 
oo Wil) “Annals of Botany 24:491-so9. pls. 37-39. figs. 2. 1910. 
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