46 Harshbcrger. — An Abnormal Development of 



A third bract is reached in acropetal succession from the 

 first (Plate V, Fig. 1, g 1 ), and in its axil a growth arises that 

 corresponds in every particular with the branch-organ already 

 described as springing from the axil of the second bract. 



The axillary position of the foliar shoots and their relation 

 to the flower-like shoot give an insight into the morphological 

 relations of the teratological parts. In the abnormal floral 

 branch (Plate V, Fig. 1, g) an indurated collection of nodular 

 bodies strikingly resembles ovarian tissue. Bract G, as we 

 have seen, subtends two branches, the lower being a veget- 

 ative shoot, the upper or superposed one resembling a flower. 

 This condition corresponds to the superposed buds met with 

 in such plants as Lonicera tartarica, which produces three to 

 six axillary buds on some shoots ; or Jnglans cinerea, in which 

 the primary axillary bud remains latent, and several accessory 

 axillary buds push out, of which one elongates into a branch. 



The histology of Dioncea has been studied and described by 

 Kurtz, 1 C. de Candolle 2 and Fraustadt, 3 though most observers 

 in their desire to study the specially interesting leaf traps, 

 have to some extent neglected the anatomy of the underground 

 parts and of the scape. The vegetative shoots above referred 

 to seemed well suited for a study of the fibro-vascular bundle 

 distribution. 



A cross section of the scape two inches below the point of 

 branching is illustrated in Plate VI, Fig. 4. The section 

 shows externally an epidermis made up of large polyhedral 

 cells. Beneath are five or six rows of loose parenchymatous 

 elements with intercellular spaces. The phloem or soft bast of 

 the bundle consists of sieve tubes and companion phloem cells, 

 while a few xylem cells are intimately connected with the 

 small phloem areas. A zone of parenchyma intervenes 

 between the small external bundle and the larger fibro-vas- 

 cular area within. The outer portion of this area is occupied 

 by the phloem, the inner by xylem, made up of pitted vessels, 

 also spiral and scalariform tracheids. The centre of the sec- 

 tion consists of cellular tissue. 



1 Archiv. fur anat. und Physio-wissen. Medicin, 1876. 



2 Archiv. de Sc. Physik. et Nat. Geneva, 1875-76. 

 sCohn's Biologie der Pflanzen, Band II, pp. 50-59. 



