I04 The Ohio Naturalist. [Vol. IV, No. 5,. 



cups and surfaces for the absorption of rain and dew. In 

 Euphorbia pulcherrima, commonly cultivated in green houses, 

 there are very large cup-shaped nectar glands, one on the 

 involucre of each cyathium. 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 insects 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 

 sticky nature to prevent crawling insects from passing 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 highl}^ developed glands while its near relatives 

 have none whatever. Even on a given individual, some leaves 

 may have the glands while others have none and rarely is the 

 number constant. 



Very common among plants is the presence of gladular hairs 

 or pubescence, like on Petunia violacea, Martynia louisiana, 

 Polanisia graveolens, Silene virginica, and Cypripedium acaule. 

 Punctate glands in the leaf blade and other parts are also abun- 

 dant as in Xanthoxylum americanum, Polygonum pnnctatum,. 

 Amorpha fruticosa, Hypericum perforatum, and Boebera papposa. 

 The latter has comparativel}- large, yellow, oval glands which 

 are very conspicuous under a hand lens. Various plants also 

 have glutinous leaves especially when >oung, but these will not 

 be considered here. 



Of plants which have glandular surfaces with digestive secre- 

 tions especially concerned in capturing and ab.sorbing other organ- 

 isms as food, we have the following : 



1. Sarracenia purpurea. 6. Utricularia intermedia. 



2. Dro-sera rotundifolia. 7. Utricularia minor. 



3. Drosera intermedia. S. Utricularia gibba. 



4. Utricularia cornuta. 9. Dipsacus sylvestris. 



5. Utricularia vul,naris. lo. vSili)liiuui perfoliatum. 



In this group probably belong such plants like Silene antirrhina 

 with glutinous bands around the stem and Cardinis 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 



