io Russell— Comparison of the Structure of Hybrid 



(PI. I, fig. 2) and extends the whole pitcher length. In S. Cates- 

 baei the wing is wider below, half as wide as in S. purpurea, 

 and of much the same shape (PI. I, fig. 3). 



In 5. purpurea the inflated pitcher is constricted below the 

 rim around the mouth (PI. I, fig. 1). In 5. flava the pitcher 

 has no suggestion of a constriction, but rather expands widely 

 at the rim. In S. Catesbaei the pitcher is slightly constricted 

 below the rim (PI. I, fig. 1), although not so strongly as in 5. 

 purpurea. 



The color of the pitchers of S. purpurea is: base green with 

 a reddish network of veins over the outer pitcher surface, par- 

 ticularly above. The lid is especially strongly marked with 

 crimson-purple reticulations. (Variations: all green; with 

 graded transitions to crimson-purple suffused over the surface 

 almost uniformly.) 5. flava, in the most common type, has 

 a greenish yellow pitcher and lid, the latter with a deep crim- 

 son patch at its base. The marking is usually band shaped, 

 about 1-2.5 cm. wide. (Variations: purplish veining on upper 

 pitcher and lid; bright green pitcher; or entire pitcher and lid 

 rich purple.) S. Catesbaei shows a variety in coloration, accord- 

 ing to the variations noted above in the parents. An average 

 type represented in fig. 3 has a green pitcher with red-purple 

 veinings, less heavily developed than in S. purpurea. The red 

 banding in the throat of the S. flava parent is reproduced, but 

 more dilute in color. (Variations: uniformly green, more pro- 

 nounced purple markings, or entirely purplish.) 



The lid shape in the three forms exhibits a nearly balanced 

 relation. In S. purpurea the lid is reniform, with an undulate 

 margin (PI. I, fig. 1). The lower lateral portions of the lid 

 are prolonged into blunt lobes, which are bent forward about 

 the mouth of the pitcher, so that it is open only from the front. 

 Instead of overhanging the pitcher opening, the lid in this spe- 

 cies is somewhat curved outwards. In S. flava, the lid is ovate- 

 cordate, but prolonged in its median portion into a tip process. 

 The sides of the lid are not lobed as deeply as in 5. purpurea, 

 but the slight auricles are here bent sharply backwards, expos- 

 ing the throat of the pitcher. The lid slightly incurves above 

 the orifice. S. Catesbaei (fig. 3) is very nearly intermediate 

 in parental characteristics. The lid is more rounded in out- 

 line than S. flava, but possesses a slight tip process, not as pro- 



