59S TRANS. ST. LOUIS ACAD. SCIENCE. 



veloped the habit of holding up their pollen until the points on 

 the anthers have been touched by a bee. The bee, on the other 

 hand, has acquired the habit of turning and hanging to the sta- 

 mens in order to dislodge the pollen with its legs, and this habi 

 is an advantage to the bee and to the flower also. G. pedicula- 

 ria and G. purpurea have, therefore, acquired a form which re- 

 quires even male bees, which do not come for pollen, to turn and 

 enter the flowers so that they will be certain to strike the anther- 

 points with their legs. Flowers of the "Tipo violacio" are apt to 

 have some intruders which suck without turning, such as Bom- 

 bylius on Viola^ and the humming-bird on G, pcdicularia. 



Castilleia cocciJiea Spreng. — The flowers are subtended by 

 broad, 3-cleft leaves, or bracts, which are bright scarlet at the 

 summit, and form the most attractive part of the inflorescence. 

 The calyx is laterally compressed, cleft in front and behind, and 

 is scarlet at the tip. The pale corolla is also compressed and is 

 included in the calyx. The lower lip is almost entirely aborted, 

 being reduced to three small points. There is, therefore, nothing 

 about the flower which can be considered as a landing-place for 

 insects. The anthers are inclosed in the upper lip, which is long 

 and narrow. The mouth of the corolla is closed. When a pencil- 

 point is thrust into the throat, the upper lip opens and is thrown 

 forward, so that the anthers are brought against the pencil. The 

 style is exserted, holding the stigma over the mouth of the flower, 

 and this also is thrown forward when anything separates the- 

 lateral edges of the mouth. The stigma strikes the visitor in ad- 

 vance of the anthers, and this secures cross-fertilization. 



The scarlet color and the absence of a landing-place suggest 

 that the flower is adapted to humming-birds, and the ruby-throat 

 {^Trochilus colubris L.) is the only visitor I have observed, al- 

 though bumble-bees and butterflies may sometimes occur, since 

 the tube is only about 15 mm. deep. The plant blooms about 

 the time of arrival of Trochilns from the south. In 18S6 the first 

 humming-bird seen was on May 5, visiting the Castilleia. 



Carlinville, III. 



