34 PRACTICAL COURSE IN BOTANY 
32. Recording observations. — For this purpose a page 
should be ruled off in the notebook of each student, after 
the model here given, and the facts brought out by the differ- 
ent experiments set down as observed. 
NuMBER OF SEEDS GERMINATED 
No. of hours .. 24 | 48 | 72 |4d./5d.)/6d./74.}8d.|10d./2 w. 
No. of vessel. . 
No. of vessel. . 
No. of vessel. . 
No. of vessel. . 
No. of vessel. . 
eye ele 
No. of vessel. . 
EXPERIMENT 26. CAN SEEDS HAVE TOO MUCH MOISTURE? — Drop a 
number of dry beans or grains of corn, oats, or other convenient seed, 
into a vessel with a bedding of cotton or paper that is barely moistened, 
and an equal number of soaked seeds of the same kind into another vessel 
with a saturated bedding of the same material. In a third vessel place 
the same number of soaked seed, covering them partially with water, and 
in a fourth cover the same number entirely. Label them 1, 2, 3, and 4; 
keep all together in a warm, even temperature, and observe at intervals 
of twenty-four hours for a week. What condition as to moisture do 
you find most favorable to germination? Would seeds germinate in the 
entire absence of moisture? How do you know? 
Exprrimient 27. Was IT THE PRESENCE OF TOO MUCH WATER, OR 
THE LACK OF AIR CAUSED BY IT, THAT INTERFERED WITH GERMINATION 
IN THE LAST EXPERIMENT? — To answer this question experimentally is 
not easy, since it is difficult te obtain a complete vacuum without special 
appliances. The simplest way is to fill with mercury a glass tube 30 
inches long, closed at one end, and invert it over a small vessel — a tea- 
cup, or an egg cup will answer — containing mercury enough to cover 
the bottom to a depth of two or three centimeters (see Appendix, Weights 
and Measures, for English equivalents.) The tube must be supported in 
such a way that its lower end will dip into the mercury without touching 
the bottom of the vessel. With a pair of forceps insert under the mouth of 
the tube two or three seeds that have been well soaked in water deprived 
of air by previous boiling. Being lighter than mercury, they will float to 
the top, where there is a complete absence of air while other conditions 
