Francis E. Lloyd —196— Carnivorous Plants 



and carrying it forward for some time, till indeed the hypocotyl reaches 

 its fullness of development, with a length of 3 mm. (79 — 1-3). By 

 this time the petioles of the cotyledons have emerged, and, just above 

 the plumule, expand to form a sack-like expansion surrounding it. 

 Above this they are suddenly constricted, the isthmus entering the 

 seed and connecting with the expanded ends of the cotyledons which 

 form a haustorium. The developing plumule breaks out of one 

 side of the surrounding cotyledonary envelope and progresses toward 

 forming the plant. The leaves of the first whorl are slender ligulate 

 and taper to a fine point, or may be variously laciniate to some de- 

 gree. There are usually five in the whorl. The next whorl, raised 

 on an evident internode, shows still more laciniations, but does not 

 yet produce traps (79-5). These, however, usually appear in the 

 fourth whorl. Subsequently the mature condition is gradually estab- 

 lished. The hypocotyl ends without forming a root cap, and initial 

 cells appear never to be established after the primary condition has 

 passed {iq — 4). This, Korzschinski, who described the course of 

 germination, did not see, and this lack was indicated by Goebel. 

 The structure of the seed and seedHng in its primary condition is 

 quite similar to that of Dionaea, as described by Smith (193 i), dif- 

 fering however in a few details, notably in the greater expansion of 

 the cotyledonary petioles to embrace the plumule, and in the failure 

 of root growth. 



The leaf of maturity. — This consists of a wedge-shaped petiole 

 (regarded by Nitschke as the leaf base {fide Troll, 1939) and the nar- 

 row isthmus between it and the trap as the petiole, a view now re- 

 garded as untenable), somewhat truncated at the apex, where it bears 

 four to six, occasionally more (eight, Caspary) serrate bristles, and at 

 its middle point a leaf blade in the form of a trap. 



When four bristles only are present they appear to stand two 

 on each side of the trap, but the inner two, as revealed during de- 

 velopment, stand somewhat behind the insertion of the trap, and 

 overlap it {19 — 6). If a fifth occurs, this quite evidently stands 

 behind the trap, and therefore does not, as Caspary noted, arise from 

 the end of the petiole, but from its dorsal surface. The bristles cannot 

 therefore be regarded as lobes of the leaf, as Cohn thought, nor 

 as stipular appendages (Nitschke, 1861), but rather as emergences. 



The structure of the petiole {19 — 9) in general is that of water 

 plants; there are wide intercellular chambers of pentagonal, hexagonal 

 (along the midrib), or elongated form (along the margins), separated 

 by partitions one cell thick. Fenner, who has more than anyone 

 else described the minutiae of the plant's structures and their de- 

 velopment, errs in showing large hexagonal chambers over the midrib, 

 and in fact the figure of his transverse section does not consist with 

 that of the leaf en face, the former being correct. The epidermis is 

 scantily clothed with two-armed trichomes {19 — 16), standing on 

 two very short stalk cells with cutinized walls, these in turn on two 

 epidermal basal cells. The arms of these hairs may be short or, es- 

 pecially along the margins, twice as long. The bristles taper grad- 

 ually from their broader bases and are serrated irregularly by 

 projecting unicellular trichomes, ending in a similar spinous one. 



