164 W. H. GILBURT ON THE HISTOLOGY OF PITCHER PLANTS. 



within verj^ wide limits, and their two ends terminate in several 

 angles, as though filling up the space formed by the partial union of 

 a number of rounded cells, and the spiral fibres are continuous over 

 their angular terminations. They appear to have no connexion with 

 the vascular system, sometimes passing across the bundles at a 

 higher or lower level. Their average diameter is often five or six 

 times that of the true vessels. 



As to the nature of these structures and their value to the 

 plant, I am not in a position to offer an opinion, and probably no 

 reliable view can be arrived at, save upon developmental evidence. 



I regret that so much of this paper has been taken up by matter 

 which largely partakes of a controversial nature ; still it is in no 

 carping spirit that I offer it, and trust that with it I have been 

 enabled to bring before you something of more general interest. 



EXPLANATION OP PLATE XL 



Fig. 1. — Section of gland from interior surface of Sarracenia pwyurea. 

 „ 2. — Section of hair from upper zone of same. 

 „ 5. — ,, „ lowest zone. 



„ 3-4. — Surface view and Section of gland from exterior of 8. Drum- 



mondii. 

 „ 6. — Outline of surface cells ; 7, — of deeper layer of B purpurea, 

 „ 8. — Small gland from interior surface of Cephalotus. 

 „ 9. — Large gland from crescentric glandular bodies of same. 

 „ 10. — Small gland produced from modification of stomata. 

 ,, 11. — Superficial aspect of exterior gland of same. 

 „ 12. — Section of hood and gland of Nepenthes clielsoni. 

 „ 13. — Thickened cells from margin of hood of same. 



Figs. 1-9 X 225 reduced one half. 

 „ 10-11 X 382 

 „ 12 X 98 

 „ 13 X 225 



