236 BOTANICAL GAZETTE [SEPTEMBER 
The structure of Podocarpus spinulosa.—Brooks and Sries" find the 
structure of the stem and leaf of Podocarpus spinulosa similar to species studied 
by PENHALLOw and Worspett. The wall of the microsporangium is described 
as similar to that of Saxegothaea and Araucaria except that the dehiscence is 
oblique. The male gametophyte agrees with P. ferruginea and P. dacrydioides, 
described by JEFFREY and CurysLER, having a prothallial complex of eight cells, 
and occasionally the appearance as of a second derivative of the generative cell. 
The course of the vascular bundles in the ovulate sporophyll is studied in detail 
and compared with other forms. 
That Podocarpus is a specialized offshoot from Saxegothaea-like ancestors 
is confirmed by the presence of less mesarch wood than in Saxegothaea, the loss of 
function of some of the resin canals, and the specialized ovulate structure with 
reduction in size and number of scales. The independence of the vascular supply 
of the ovule from that of the scale is explained by the greater importance of the 
ovule in Podocarpus. The authors regard Podocarpineae as a natural group, 
with no very definite connection with Taxineae, no evident relation to Abietineae, 
but with a probable connection with Araucarineae-—Mary S. YOUNG. 
Evolution of plants.—In his presidential address of 1910 before the Lin- 
nean Society of London, Proressor Scorr selected as his subject “Some 
modern ideas on the course of evolution of plants.” It is an outline of the 
present status of opinion in reference to the evolution of vascular plants, 
especially as developed by the recent rapid increase of knowledge of paleo- 
botanical material, and is in part a confession of faith. The author evidently 
believes in the homologous origin of the alternation of generations, and regards 
the sporophyte of the pteridophyte as developed directly from the thallophyte 
body. Special attention is given to the views of LIGNIER in connection with 
this thalloid origin of the cormophyte. The classification of vascular plants 
proposed in the new edition of his Studies in fossil botany is outlined, and the 
gymnosperm relationships are discussed; while Bennettitales-like forms are 
still put forward as representing a possible origin of the angiosperms. ran 
the main thesis of the address is to illustrate among plants the Ceery of 
GASKELL, developed in a discussion of the origin of vertebrates, that “each 
successive group has arisen from some member of the highest group €X!S sah 
at the time.”—J. M. C 
Evolution of Pinus.—Baitry'? has presented the anatomical characters 
that seem to be of service in tracing the lines of descent of pines. The creta- 
ceous pines and Prepinus are characterized by thick-walled ray parenchym, 
“piciform ” lateral ray pits, absence of marginal ray tracheids, 
*« Broos, M. A., and Stites, W., The structure of Podocarp spinulos® Annals 
of Botany 24:305-318. pl. 21. 1910. 
2 Bartey, Irvine W., Anatomical characters in the evolution of Pinus: Amer. 
Nat. 44:284~-293. 1910. 
a 
i 
: 
IS me il ee ey, = ae aie — + rf eal) So ho aap Na 7 Ee = 
FE a en ee Tee Re eT A OE ee Rage StS Ef RE Ee Te eae aS IN ee oe ee ALCP Ee ee 
Se ape eS ae ile Rp ee ee ea ea ee Re ar el on 
and abundant 
