1J,2 BOTANICAL GAZETTE. 



green one with withered spikes of empty sporangia, another one with 

 matured fruit, and a minute young frond; rootlets profuse, stout, 

 forking dichotoraously. Sterile segment undulate, divisions 1-4, 

 sometimes forking once or twice, acutish, pendulous, sinuses wrinkled 

 or plicate. Fertile segments or "spikes" 1-4, arising at intervals or 

 clustered from the stipe, the basal margins, or the intramarginal lam- 

 ina near the base of the sterile segment, recurved; peduncles 6 lines 

 long, spikes 6 lines to one inch long and one line broad; sporangia 

 14-20 pairs. 



The external structure of the frond in this species as also in 0. pen- 

 dulum, indicates the unity of the barren and fertile parts in Ophioglos- 

 sacefe, and that together they constitute a "branched leaf." (Sachs) 

 This theory is in opposition to the earlier hypothesis of a cohesion of 

 the two spikes of a barren and of a fertile frond. In 0. palmatum, 

 therefore, the highly developed frond may be described as branching 

 into one barren, and numerous fertile, segments; the former again 

 dividing into dichotomously forking lobes. 



Branching thus like the horns of elks, and thick and fleshy in tex- 

 ture while living, this curious epiphyte has probably recalled to oth- 

 ers as well as myself, the exotic Fern, which is often seen attached to 

 the wall of conservatories, Platijcerium alcicorne. 



The species is so distinct from all its congeners, that Presl founded 

 upon it a separate genus, which he called Cheiroglossum., in allusion 

 to the resemblance of the sterile segment to a liand, and of the fertile 

 ones to tongues. — John Donnell Smith. 



Phyllotaxy of Leaves, by A. P. Morgan (concluded from Feb. 

 Gazette). — 1.5. The secondary spirals are of essential service in de- 

 termin'.ng the arrangement of the leaves when they are thickly crowd- 

 ed upon the stem, as is the case with the leaves of the Houseleek and 

 the scales of Pine Cones. The intermediate spirals are the most 

 plainly to be seen ; those adjacent to the vertical ranks and to the 

 primary spiral are the most obscure. Having determined two con- 

 secutive orders of spirals, one winding to the right and the other 

 winding to the left, the sum of their numbers of spirals gives the next 

 higher order of spirals, and their difference gives the next lower or- 

 der. The other orders of spirals may be determined in like manner 

 until the primary generating spiral and the vertical ranks are reached. 



16. A single example will illustrate the manner of finding the cy- 

 cle by means of the secondary spirals. Take for example the cone 

 of the White Pine (Pinus Strohus) (Figs. 5 and 6). The process of 



