160 
freely and producing roots and small tubers within 
the large seed tuber. The potatoes were stored 
in a dry room lighted with diffuse daylight. 
Sprouts of one tuber never penetrated an adjacent 
one. Investigation failed to show the presence of 
any enzymes by the action of which the channels 
of the ingrowing sprouts could have been digested, 
though the epidermis of the sprouts was modified 
so as to resemble typical glandular epithelium, 
thus suggesting secretion. There was positive evi- 
dence that the sprouts made their way through the 
tissue by mechanical pressure. Attempts experi- 
mentally to produce penetration of tubers by 
potato sprouts met with success, except that the 
sprouts were unable to penetrate through the epi- 
dermis from the outside. These experiments, in 
connection with the behavior of the original ab- 
normality, led to the high probability of a reversal 
of polarity in the shoots. The cause of tuber- 
formation in general was briefly discussed, as was 
also the bearing of the ingrowing sprouts on the 
question of the mode of emergence of lateral roots. 
The Gametophytes of the Kauri: ARTHUR J. 
EaMEs, Harvard University. 
The microspore contains many supernumerary 
prothalial nuclei. Its branching tubes penetrate 
the scale-base and the axis, thence crossing the 
space to the nucellus which is largely eroded, with 
portions of the endosperm. The megaspore, devel- 
oping at first within ‘‘spongy-tissue,’’ forms a 
club-shaped embryo-sac, bearing 6-20 archegonia. 
A small ephemeral ventral canal nucleus is cut off. 
Fertilization occurs usually in lower archegonia, 
the two large male nuclei being shunted from the 
upper egg-cells by a cap of the megaspore mem- 
brane which is thickened rather than thin as in 
most conifers. The pro-embryo maintains a cen- 
tral position in the archegonium in contrast to the 
condition in other groups until at least 32 nuclei 
are formed. Then nuclear enlargement and wall- 
formation ensue, filling the archegonium. The 
upper 20 or more cells become suspensors, the 
central group, consisting of a few cells, the embryo 
proper, and the basal tier a marked protective cap. 
The large core of suspensors thrust down the two 
lower tiers deep into the endosperm, where in 
further development the cap is pushed aside and 
degenerates. 
The Gametophytes of Australasian Podocarps: 
Epmunp W. Sinnott, Harvard University. 
The gametophytes and embryo of Podocarpus 
Totara, Hallii, nivalis, dacrydioides, spicatus and 
ferrugineus have been investigated. Observations 
SCIENCE 
[N.S. Vou, XXXV. No. 891 
on the male gametophyte add to previous accounts, 
but agree in general with them. In the first four 
species (Podocarpus proper) three or four months 
elapse between the appearance of the megaspo- 
rangium and the ripening of the fruit, and the 
development of the endosperm, archegonia, and 
embryo is much as in the Abietinem. In all spe- 
cies, even a ventral-canal nucleus is uncommon. 
There are from eight to sixteen suspensors. The 
last two species (subgenus Prumnopitys) are very 
distinct. The reproductive process extends over 
sixteen months. The two very large archegonia 
are narrowed at the base. The fusion nucleus 
divides into four as it drops and the eight subse- 
quent basal nuclei are irregularly arranged, as are 
the sixteen cells which follow them. The young 
embryo has a ‘‘penetrating cap.’’ Both species 
of the subgenus Prumnopitys show a marked re- 
semblance to Cephalotazus, and further investiga- 
tion promises interesting results as to the relation- 
ship of the two genera. 
The following list of papers, from members of 
the society, or members of Section G, to be intro- 
duced by members of the Botanical Society of 
America, were received too late to be included in 
the printed program and were read by title: 
Acidity as a Factor in Plant Ecology: F. V. 
CoviLLE, U. 8S. Department of Agriculture. 
The Cultivation of Trailing Arbutus: F. V. 
CoviLLE, U. S. Department of Agriculture. 
Ecology as Applied to the Revegetation of Over- 
grazed Range Lands: A. W. Sampson, U. S. 
Department of Agriculture. 
The Relation of Soil Acidity to Plant Societies: 
A. W. Sampson, U. S. Department of Agricul- 
ture. 
The Effect of a 2 per cent. Aqueous Solution of 
Antipyrin on the Cells of the Root-tip of Vicia 
faba: C. F. Horrss, University of Mlinois. 
On the Acidity of Certain Cacti: H. M. RicHarps, 
Columbia University. 
Conditions Affecting the Production of Lycopin in 
the Tomato: B. M. Ducear, Cornell University. 
Senility in Meristematic Tissue: H. M. BENEDICT, 
University of Cincinnati. 
A Botanical Survey of Hartsville, S. C.: W. C. 
CoKER, University of North Carolina. 
The Biology of the Lakes of Glacier: M. J. 
Exrop, University of Montana. 
The Cytclogy of Laboulbenia chartophora: J, H. 
FavuLu, University of Toronto. 
Grorce T. Moore, 
Secretary 
