1910] _ CURRENT LITERATURE 473 
balance with the Na+ and K+ taken up was due to the toxic conditions of the 
experiments. He ends by saying that NATHANSOHN’s methods are not at all 
reliable for permeability measurements, and that they cannot be taken as the 
basis of any explanation of the regulatory permeability of the Plasmahaut.— 
WILLIAM CROCKER 
Fossil woods of Germany.— GorTHAN”® has described two fossil woods occur- 
ring in the brown coals at Senftenberg, from the Lower Miocene. One is a 
Cupressinoxylon type, Taxodioxylon sequoianum Gothan, the structure corre- 
sponding to that of Sequoia sempervirens. The Cupressinoxylon type of wood 
in this locality, as in general, is the form most abundantly represented in the 
brown coals of the Miocene as well as in the Oligocene. The reference of this 
wood to Sequoia sempervirens, or to a closely related species, is in accordance 
with reports by WEBER, according to whom leaf impressions in beds of similar 
age at Bonn all belong to Seguoita Langsdorfii. The second wood described is 
that of a new species of pine, Pinus parryoides. Although woods of the Abietineae 
are not nearly so abundant in the brown coals of this horizon as are those o 
Taxodioxylon structure, they are not rare, and always belong to the group with 
resin ducts. The epithelium cell walls of the resin ducts of the new pine are 
provided with pores like those of Picea and Larix, a character not found in any of 
the recent pines. The question as to its true position is considered at some 
length, the author arriving at the conclusion that it is the wood of a true Pinus, 
the character at variance having been lost in recent forms, and that it should be 
placed in either §PARRYA or §BALFouRIA. Representatives of either of these 
sections are found only in western North America and eastern Asia.—REINHARDT 
THIESSEN 
Morphology of Juniperus.—NiIcHOLS?? has made a detailed study of the 
morphology of the American variety (depressa) of Juniperus communis, obtaining 
his material from three seasons of collecting near New Haven, Conn. Naturally 
it is largely confirmatory of the work of Nortén, StupsKyY, and Miss OrTTLey, but 
is especially interesting in its establishment of the time intervals. The staminate 
strobilus begins to develop during the summer of the year preceding pollination, 
the mother cells enter into the synapsis stage about May 1, and there is a period of 
about twelve and one-half months between pollination (May 25) and fertilization. 
The ovulate strobili begin to appear a few weeks before pollination, the megaspore 
tetrad is formed late in April, and the female gametophyte develops in about six 
weeks. The body cell and the central cell divide about three days before fertiliza- 
tion, so that at fusion the egg and sperm are not more than three days old. Some 
of the more interesting details are as follows: the wall of the microsporangium 
28 GoTHAN, W., Ueber Braunkohlenhéjzer des rheinischen Tertaers. Jahrb. 
Konig. Preuss. Geol. Landesanstalt 30:516-532. 1900. 
20 NicHoLts, GEORGE E., A morphological study of Juniperus communis var. 
depressa. Beih. Bot. Centralbl. 25:201-241. pls. 8-17. figs. 4. 1910. 
