90 
COROLLA. 
5th. Papilionaceous , (Fig. 26) a 
flower with a banner, two wings, 
and a keel : the name is derived 
from the word papilio, a butter- 
fly, on account of a supposed re- 
semblance in form, as the pea 
blossom. 
If a corolla, in shape, is not like 
any of the forms we have described, 
it is said to be anomalous , which 
signifies without law or rule.* 
Odour of Flowers. 
The odour of flowers has its origin in the volatile oils, elabo- 
rated by the corolla : its production results from causes both ex- 
ternal and internal, but equally beyond our observation. 
Temperature renders the odours of flowers more or less sen- 
sible ; if the heat is powerful, it dissipates the volatile oils more 
rapidly than they are renewed ; if the heat is very feeble, the 
volatile oils remain concentrated in the little cells where they 
were elaborated ; in both cases the flowers appear to possess but 
little odour. 
But if the heat is neither too great nor too little, the volatile oils 
exhale without being dissipated, forming a perfumed atmosphere 
around the flowers. 
You see now, why it is, that when you walk in a flower gar- 
den in the morning, or towards evening, the flowers seem more 
fragrant, than in the middle of the day. Humidity in the air 
* It is proper here to observe two important facts connected with the de- 
scriptions of plants, which are made by references to natural and artificial 
forms. 
“ 1st. A certain number of forms were assumed by Linnaeus as standards 
for references ; none of which arc to be considered as perfect But when 
nay one of these forms is referred to, it is to be understood that it is near- 
er the true form of the organ under consideration, than any other of theso 
standard forms. 
2d. All standard forms are either drawn from well known natural bodies, 
or from artificial bodies, or implements known to the ancients. Some of 
the most common natural bodies are the egg, lips of animals, the throat, 
head, knee, the heart, the kidneys, the hand, bird’s feet, spur, feather, 
tooth, hair, bristles, silk, down, eye lashes, veins, nerves, wings, ears, claws, 
&c. Some of the most common artificial bodies or implements arc a spike, 
spindle, circle, oval, lance, line, awl, arrow, halbert, viol, lyre, saw, shield, 
cross, sabre, needle, bell, keel, club, cone, leather, cup, fork, urn, wheel, &c.” 
— Eaton. 
Fig. 26. 
Papilionaceous — anomalous corollas — origin of the odour of flowers — 
odour affected by temperature — 
