Dogbane and Milkweed 309 



butterfly's preserves. For this intrusion he is 

 dealt with as severely as poachers were under the 

 forest-laws of feudal England. 



There is another variety of dogbane, the Indian- 

 hemp, or Apocynum cannabinum, which bears 

 smaller blossoms than the androsaemifolium, blooms 

 somewhat later, and is more widely distributed 

 over the country. This flower has no callosities 

 in its corolla, sets no scares for insect victims, and 

 is apparently quite innocent of the crimes which 

 one is inclined to lay to the charge of its first 

 cousin. 



The common milkweed (Asclepias cornuti) (Fig. 

 86) also imprisons insects, which sometimes die in 

 captivity, and do no apparent good to the plant 

 by their deaths. They have, however, invited mis- 

 fortune, for though the milkweed is rich in honey 

 and is visited by a large and miscellaneous com- 

 pany, it can be fertilized, apparently only by bees, 

 and perhaps by a few large flies. 



The milkweed is a peculiarly - constructed and 

 very highly-organized flower. The sepals and the 

 petals, each five in number, fold back as soon as 

 the flower opens and press closely against the 

 flower-stalk (Fig, 87, a). Inside them, standing 

 upright in a ring, are five honey-jars or nectaries 



