THE GUIDE TO NATURE 
i iS 
FIG. 1— GENERAL FORM AND VARIABLE TYPE HAIRS ON LEAF OF COMMON HOUSE 
GERANIUM. 
The flared tip form is found but seldom. 
painted, things we have passed per- 
haps a hundred times, nor cared to see,” 
I have “painted” a few of the hairs from 
a haphazard collection of dead leaves in 
order to direct your attention to com- 
mon things we “nor cared to see.” A 
handful of old leaves holds open- 
mouthed wonder for the uninitiated 
and hours of delight for the micros- 
copist. 
For the most part, the hairs on plants 
are clearly crystalline, glasslike forms, 
though some hold delicate hues of 
color, especially during the transition 
stage while drying. 
In structure, the commonest form 
will be type agreeing most nearly with 
popular belief — merely a slender, coni- 
cal filament as seen in the specimen 
(Figure i A) from our African immi- 
grant, the common “geranium” ( Pelar- 
gonium ) of our window garden. 
Don’t pass them hastily merely be- 
cause at first glance they may seem of 
the “common type” for, if you do, you 
will miss much. Even this form has 
many variations from the short, stubby 
form (Figure 2) of many cells through 
many variations to. perhaps the other 
limit in the single-celled, extremely 
tenuous form of the cotton fibre. In 
the immature state it is a slender tube 
about a fifteen-hundredth of an inch in 
diameter and three or four inches long. 
In the dried state it flattens and crin- 
kles into the familiar typical form 
shown in our picture (Figure 7). Com- 
mon cotton wrapping cord yields good 
specimens. No doubt you will find a 
small snarl of this among the old 
leaves. 
While most of the hairs on the 
geranium leaf are like the large, sepa- 
rate specimen, an occasional mimetic 
form will be found like the ones seen in 
the smaller forms in the same picture. 
(Figure iB.) 
Hardly any neglected back yard that 
has been permitted to “grow wild” but 
will contain its specimen of that most 
plebeian of weeds with the pretentious 
appellation of Ambrosia — food for the 
gods — but more profanely dubbed 
“ragweed.” “It must be food for the 
gods,” says our beloved Burroughs, 
“for nothing else will eat it except, 
perhaps a goat.” However, its dirty, 
unkempt leaves with their gritty, 
glassy-like crunch between the fingers 
at once suggest “something different” 
and its hairs live up to the expectation. 
These are mostly short, stubby, stiff. 
