1887. | BOTANICAL GAZETTE. 207 
able that the present ecidium has no connection with our 
known Gymnosporangia, and that its other stages may very 
likely be traced to other Uredinee which inhabit warmer 
regions near the Gulf of Mexico and the Atlantic. The re- 
Insect relations of certain Asclepiads. I. 
CHARLES ROBERTSON. 
(WITH PLATE XI.) 
ASCLEPIAS VERTICILLATA.—The gynostegium is very 
small, the anther wings measuring about one and two- 
fifths millimetres. It fastens the corpuscula almost exclu- 
Phex, those of this plant are rarely found even on the claws 
of the smallest, Ceratina dupla, Halictus, and Cerceris com- 
Pacta ninety-two specimens bearing corpuscula, 
eighty -eight have them on hairs alone, and four on the hairs 
and ¢] That is, one specimen in twenty-three has them 
Puscula of A. incarnata has them on its claws. As the wings 
crease in size in the three following species, corpuscula are 
attached more frequently to the claws and less often to the 
hairs, Eight specimens show pollinia on their tongues. 
ere is quite a contrast between this species and A. incar- 
Nata, in respect to the formation of combinations of corpus- 
Cula. A, verticillata does not form them so readily ; and, in 
