HoLLOWAY. — Six New Zealand Species of Lycopodium. 367 



Additional Points of Intere.st noted in the Course of this Study. 



^ Stem- apex. — Plate XXXII, fig. 7, shows the apex of a terminal branchlet 

 of L. densutn in longitudinal section ; Plate XXXII, fig. 8, the apex of a 

 young strobilus of L. volubile. 



Branching of the Stem. — Stem-branching is dichotomous in the genus 

 Lycopodium. Three consecutive sections are figured at Plate XXXII, 

 figs. 9-11, of a very early stage in the dichotomous branching of the stem 

 of L. volubile. The sections, unfortunately, were not taken quite in the plane 

 of branching, but their general outline shows sufficiently clearly that a true 

 dichotomy has taken place. 



Mucilage. — L. volubile is a scrambler, and its adventitious roots are 

 often to be seen' growing to the length of 2-5 ft. before they reach the ground. 

 During the wet season, in the latter part of the winter, the season of the 

 greatest growth, when these roots are growing very fast, a very character- 

 istic feature to be observed is the large thick coating of mucilage which 

 envelopes from 3-12 in. in length of the growing root-tip. Mucilage is also 

 to be found on the adventitious roots of L. scariosum and L. cernuum, though 

 in these species it occurs to a much less extent, owing to the fact that the 

 stems grow close to the ground, and the adventitious roots are consequently 

 short. 



Possibly this mucilage functions as a protection for the growing root, 

 keeping its delicate tissues moist till it reaches the ground. This mucilage 

 after a period of dry weather shows only as a dry membranous skin, and if 

 the dry weather persists the root-tip withers. 



Root-apex. — Plate XXXII, fig. 5, shows a longitudinal section of the apex 

 of an adventitious root of L. volubile. Plate XXXII, fig. 6, shows a region 

 of the piliferous layer of the same root behind the apex, with the mother 

 cells of the hairs cut off from the epidermal cells. 



Conclusion. 

 I. Classification of the Six Species. 



The study of the arrangement of stelar tissues in the above six species 

 of Lycopodium seems to indicate th^t there are two distinct types under 

 which they should be classified — viz., the " mixed " type and the " definite " 

 or " banded " type ; the banded type to be further subdivided into the 

 " radially " banded and the " parallel " banded. It will be best to clearly 

 define these terms as here used. The term " mixed " signifies the indis- 

 criminate indefinite arrangement of the xylem and phloem in the stele, the 

 loose way in which the xylem elements especially cohere together into 

 groups and bands, the way in which the phloem is indiscriminately scat- 

 tered between the various xylem groups, the spreading-out of the protoxylem 

 around the periphery of the stele. The term " banded " signifies the steady 

 coherency of the xylem elements into bands or plates of tissue, and the 

 aggregation of the protoxylem into compact groups at the extremities of 

 these bands at the periphery of the stele. The term " radially " banded is 

 applied to that arrangement of these bands or plates in which they are seen 

 to radiate from the centre of the stele like the spokes of a wheel. This 

 radial type is seen best in the young plants of many species and in the 

 small branchlets of mature plants, where the plates are from three to five 

 in number. The term " parallel " banded is applied to that arrangement of 



