APPENDIX II 
LABORATORY DIRECTIONS 
For much more detailed laboratory work than has been outlined in 
the present book see Bergen and Davis’ Laboratory and Field Manual 
of Botany (Ginn & Company). A series of type studies of spore-plants 
‘ and of representative species of seven families of seed-plants is there 
given, and the subject of ecology is treated with some care. The 
selection, preservation, and preparation of material for histological 
work is carefully described. A glossary of botanical terms is given 
in the Manual. 
APPARATUS 
The equipment of apparatus necessary for the laboratory and for 
the individual student is discussed in the Manual. Some special 
pieces of apparatus may, however, be mentioned in this place. For 
experiments on the relation of temperature to the germination of 
seeds, and for determining the highest temperatures which blue-green 
alge, bacteria, or other organisms can support, it is convenient to have 
a small, warm chamber, or incubator (thermostat). Such a chamber 
of 22 x 30 X 22 cm. inside dimensions may be had of Eimer & Amend, 
205-211 Third Ave., New York, for $40, and larger ones at higher 
prices if desired. For some purposes a differential thermostat, as 
described by Professor W. F. Ganong,? is still better. 
The apparatus to measure sap pressure (p. 47) may, as suggested 
by Professor Ganong, advantageously be replaced by a pressure-gauge 
consisting of a column of air contained in a perfectly cylindrical 
glass tube, closed at the upper end. Before such a gauge is used 
Boyle’s law for pressure and volume of gases should be explained to 
the class and experimentally illustrated. 
1 Laboratory Course in Plant Physiology, Henry Holt & Co., New York. 
362 
