APPENDIX ON PRACTICAL WORK. I5I 
6. Andrectum.—When the stamens are double the number of the 
petals, both the typical whorls are present (p. 82). If equal in number, 
the inner stamens have generally been suppressed (see above, formulze 
for carrot and grasses). More rarely (see formula for primrose) the 
outer stamens are suppressed. It is easy to tell which whorl is left, for 
the outer stamens alternate with the petals, while the inner ones are 
superposed to them. If the stamens are fewer than the petals, they 
usually represent part of the outer whorl (see formula for orchis). 
7. Gynecitum.—This is typically composed of two whorls of carpels, 
but do not put o to represent the usually suppressed whorl, as it is 
not possible in many cases to tell easily whech whorl is suppressed. 
Thus the formula for gorse is properly (p. 103)— 
Ca (5), Co 5, An (5 +5), Gn 1+0, 
but it is enough to write Gn I. 
Superior and Inferior.—If, as in hypogynous and perigynous flowers, 
the ovary is free, term it superior ; if, as in epigynous flowers, adherent 
to the cup-shaped receptacle, inferior. 
Placentation.—In most cases a transverse cut will show this. If not, 
divide another specimen longitudinally. This will show erect and 
ascending ovules. Determine the number of ovules if a few only are 
present. When they are very numerous, write indefinite (co ). 
8. Nectaries—These vary immensely in size, nature, and position. 
They may be mere points, streaks, or surfaces where nectar is excreted, 
but, on the other hand, may be conspicuous projections. They are so 
placed that the stigma, or anthers, or both, must be touched before an 
insect can reach them. The chief situations are :—(a.) on receptacle 
(wallflower, willow, mignonette) ; (b.) as a spur to calyx (garden nas- 
turtium) ; (c.) on corolla, as glandular spots (buttercup), or spurs (lark- 
spur) ; (d.) on andracium (pansy, fig. 51); (e.) on ovary (dead nettle). 
9. Protection and Pollination.—Note characteristics of wind-pollinated 
and insect-pollinated flowers (pp. 115, 118). Do not immediately con- 
clude that an inconspicuous flower is wind-pollinated, for it may make up 
for want of brilliancy by the possession of nectar (e.g., willow and lime) 
or scent (e.g., lime). If flowers are present in all stages, it is easy to 
determine whether proterandry or proterogyny obtains. The stamens 
will be dehiscing, in the former case, in very young flowers ; vice versé in 
the latter case. 
VIII. Fruirs anp Sreeps.—First master the main divisions of the 
table on pp. 136-139, and then attack the sub-divisions, examining for 
yourself as many of the examples as you can get. For dehiscence very 
ripe fruits are necessary. 
Spurious fruits will give little trouble. All the common kinds are 
described on pp. 136-139. 
Arrangement of seeds in the fruit is determined like that of ovules in 
the ovary (see above). 
For the structure of seeds examine the types described on pp. 
132-134. 
IX. CLAssIFICATION.—First determine the sub-division, class, sub- 
class, and series, by means of the following table. Remember that 
here are no sharp boundary-lines in Nature, so that a plant need not 
