76 BOTANICAL GAZETTE [JANUARY 
with the three subdivisions indicated. This conclusion depends upon the view that 
the structure of the ovulate cone, especially its vascular structure, is the paramount 
feature in determining relationship. An interesting incidental suggestion (fol- 
lowing BERTRAND) is that the aril of Saxegothaea is the equivalent of the ligule 
of Araucaria and the ovuliferous scale of other conifers.—J. M. C 
A primitive lichen.—Boirydina vulgaris, regarded in general as a problematical 
green alga, has now been investigated by Miss AcTon.3?__ It occurs as dark green, 
globular structures, which in the material examined were covering the shoots of 
a moss anda liverwort. Each one of these structures proved to consist of a central 
group of algal cells imbedded in mucilage, which in turn was traversed by invest- 
ing fungal hyphae that formed also a colorless envelope of considerable thickness. 
The cultures showed that both the alga and the fungus are “‘able to develop 
quite well apart, and multiplication of Botrydina is probably due to this.” Since 
this structure consists of an alga and a fungus growing symbiotically, the con- . 
clusion is that it should be regarded as a lichen, and that it is ‘‘possibly one of the 
most primitive of existing lichens.” The alga and the fungus were both deter- 
mined, and the habitat is said to be ‘‘in damp shady situations among various 
bryophytes, generally on rocks, but sometimes on damp ground.’’—J. M 
Movements of Myriophyllum leaves.—WACHTER has recorded33 some inter- 
esting phenomena regarding the young leaves of Myriophyllum proserpinacoides. 
The leaves of both the land and water form of this plant have already been known 
to execute so-called sleep movements, so long as they are capable of growth; 
and such movements would be very properly called photonastic.3+ In studying 
these movements WACHTER has discovered that leaves which had almost or 
quite ceased to respond to light would resume these curvatures if the shoot were 
decapitated. This seems to be a phenomenon analogous to the reactivation of 
growth in the nodes of grasses under a gravity stimulus, and still more like the 
reaction of certain conifers to decapitation, though different in details from either. 
It has also relations to the excitation of growth by a wound stimulus, and com- 
pensative growth such as that in Streptocarpus when the big cotyledon is removed © 
or incased in plaster and the small one resumes its development.—C. R. 
The mycorhiza of Cordaites.—Amyelon radicans is a root of the Coal Meas- 
ures, which has been shown to belong to Cordaites. It bears such remarkable 
and irregularly arranged bunches of lateral roots, that OsBoRN35 has examined 
32 ACTON, ELIzABETH, Botrydina vulgaris Brebisson, a primitive lichen. Annals 
of Botany 23:579-585. pl. 44. 1909. 
33 WACHTER, W., Beobachtungen iiber die Bewegungenm der Blatter von Myrio- 
phyllum proserpinacoides. Jahrb. Wiss. Bot. 46:418-442. figs. 2. 1909. 
34 Cf. Bot. GAZETTE 48: 313. 1909. 
35 OsBoRN, T. G. B., The lateral roots of Amyelon radicans Will., and their myCo- 
rhiza. Annals of Botany 23:603-611. pls. 46, 47. 1909. 
