104 
The Ohio Naturalist. 
[Vol. IV, No. 5 ^ 
cups and surfaces for the absorption of rain and dew. In 
Euphorbia pulcherriina, commonly cultivated in green houses, 
there are very large cup-shaped -nectar glands, one on the 
involucre of each C5'athium. There are also stipular glands and 
glands on top of the petiole at the base of the blade. Ants visit 
the large glands very extensively and one might be inclined to 
believe that in such cases the foliar glands are guides to the more 
abundant sweets to be found higher up when the plant is in 
bloom. In the case of submerged water plants, as for example 
in certain species of Potamogeton with glands on the leaves, the 
entire question of a relationship between in.sects and glands in 
general is eliminated. 
Besides nectar there are various other secretions : important 
among which are those with a digestive function and those of a 
stick}’ nature to prevent crawling insects from pa.ssing certain 
parts or for holding them fast while they die and decay. 
During the past summer, the writer spent some time in study- 
ing the glands which appear on the blades, petioles, stipules, and 
other parts of our native and cultivated plants. The mode of 
occurrence and the character of these organs is quite erratic. A 
species may have higlil}’ developed glands while its near relatives 
have none whatever. Even on a given individual, some leaves 
ma}’ have the glands while others have none and rarely is the 
number constant. 
\’ery common among plants is the presence of gladular hairs 
or pubescence, like on Petunia violacea, Martynia louisiana,. 
Polanisia graveolens, Silene virginica, and C\'pripediuni acaule. 
Punctate glands in the leaf blade and other parts are also abun- 
dant as in Xanthoxylum americanum. Polygonum punctatum, 
Amorpha fruticosa, H5'pericum perforatum, and Boebera papposa. 
The latter has comparativeh’ large, 3'ellow, oval glands which 
are very conspicuous under a hand lens. \’arious plants also 
have glutinous leaves especiall}' when young, but these will not 
be considered here. 
Of plants which have glandular surfaces with digestive secre- 
tions especially concerned in capturing and absorbing other organ- 
isms as food, we have the following : 
1. Sarracenia purpurea. 
2. Drosera rotundifolia. 
3. Drosera intermedia. 
4. I'tricularia cornuta. 
5. Utricularia vulgaris. 
6. Utricularia intermedia. 
7. Utricularia minor. 
<S. Utricularia gibba. 
9. Dipsacus sylvestris. 
10. Siljdiium perfoliatuni. 
In this group probably belong such plants like Silene antirrhina 
with glutinous bands around the stem and Car-tltius undulatus, 
a western species, in which the outer surface of the involucral 
bracts are very glutinous and catch large numbers of ants which 
attempt to reach the flowers above, as well as small flying insects. 
It seems reasonable to suppose that the debris from these decaying: 
