416 DR. J. D. HOOKER ON THE ORIGIN AND DEVELOPMENT 



more evident cuticle to the whole surface of the cone, except over the gland, which now 

 appears to be a secreting surface, and is rather pulpy or \iscid. 



At the next succeeding period, when the whole body is about ro-^oth of an inch long, 

 a considerable further change has taken place (fig. 4). The contraction towards the middle 

 has greatly lengthened and forms a neck, which separates an elongated conical base (the 

 futm-e lamina) from an oblong terminal body (the future pitcher). The groove is still 

 shallow on the intermediate portion (the excurrent midrib) and on the pitcher above it, 

 hut is deepened into a canal with incurved edges on the lamina below it. The gland is 

 now a deep cavity, Avith a large quadrangular orifice, over which hangs the incurved apex 

 (the lid of the future pitcher) of the original conical body. A vertical section (fig. 5) 

 through the centre shows a narrow pale line ascending close to the dorsal margin, curving 

 over the apex and terminating in the incurved apex ; this line indicates the position of 

 the future vascular bundles. At fig. 4 a minute conical body is seen at the base of the 

 groove, and is a nascent second leaf. 



At the next following marked stage, the lamina, excurrent midrib, and pitcher are 

 externally very well defined, and the lid of the pitcher differentiated. The lamina is still 

 a cone, but much elongated, and presents a cylindrical groove with the edges slightly 

 turned in, representing the earliest appearance of that organ in its involute condition of 

 vernation. The contracted portion above it (the excurrent midrib) has elongated more in 

 proportion than the lamina or pitcher, and its frontal groove is less marked. The apex of 

 the pitcher has grown upwards and backwards ; the incurved portion, again, has so grown 

 do^-nwards as to close the orifice of the cavity. On a vertical section (fig. 7) the cavity 

 is seen to be prolonged downwards as a sac parallel to the walls of the pitcher, whilst the 

 incurved portion or lid has both grown downwards over the mouth of the cavity, and 

 inwards towards its dorsal face ; its protuberant inner surface is more papillose than any 

 part of the sac. As the pitcher enlarges, the apex, which points upwards and backwards, 

 elongates, at first considerably more than the lid itself, and becomes the styliform process 

 at the jimction of the lid and pitcher. On a vertical section (fig. 8) the vascidar bundle is 

 seen to run up to the apex of this process, which thus continues to be the true organic 

 apex of the whole foliar organ. 



The succeeding stages of growth were examined in N. Hafflesiana and phyllamphora ?, 

 and present few external characters but what have been previously observed. In the 

 former species the terminal process often spreads and divides, and, together with the 

 whole pitcher, is covered vaih. appressed hau's. These hairs point upwards everywhere 

 except on the young lid, where they either project or point in the opposite direction. On 

 a vertical section at this time, the lid is found to have reached the lower portion of the 

 orifice, and it afterwards closes the mouth of the pitcher (fig. 10) ; and one or two recur- 

 rent fascicles of vessels are found to originate in the principal vascular bundle in its 

 course towards the apex of the young styliform process, which bundles enter the sub- 

 stance of the Ud, and ramify in it. 



The vernation of the leaf in Nepenthes is well known to be involute, the opposite 

 margins being each rolled in towards the midrib. This curious arrangement, which is 

 not peculiar to the genus, appears to me to be a secondary one, or rather an induced con- 



