2 1 ' 

 5 5 



94 PROCEEDINGS OF SOCIETIES. 



in the measurements, even in the cells of a single specimen, they could 

 not be relied upon as characteristics of any species. The form, how- 

 ever, of the cells, the thickened or delicate cell-wall, the character of tlie 

 contents, and the presence or absence of trigones at the angles of the 

 cells he considered as of importance in determining the species. The 

 ])aper was illustrated by drawings and specimens under the microscope. 

 — " Notes on the Distribution of Alc/rn.'" Ey George Dickie, M.D., Pro- 

 fessor of Botany, Aberdeen. (See p. 70.) — " On the Flora of the South 

 of France." By James F. Eobinson. Communicated by JMr. Sadler. — 

 "Memoranda on Fir-cones chiefly in the Museum of Economic Botany, 

 Etiin. lloyal Bot. Garden." By Professor A. Dickson, Glasgow. Dr. 

 Dickson demonstrated some of the forms of spirals occurnng in the 

 cones of the Spruce Fir {/Jbies exceha) by means of specimens where the 

 cone-scales were nund)creil with oil-paint, different colours being used 

 where desirable. The paint was allowed to dry, and then the cones were 

 put up in jars with strong solution of salt. In this way he exhibited the 

 following forms : — ^V spiral (the normal form) ; -^ spiral ; -^-^ spiral ; 

 and conjugate double (bijagate) -JL—{=-^^) spiral.* Dr. Dickson stated 

 that while working at these cones he took occasion (by permission of 

 Professor Ballbur) to examine the collection of cones in the museum at 

 the Edinburgh Botanic Garden, among which he noted the following : 

 — A. Belonging to the ordinary series, \, \, ^, f, etc. Pinus Pinader 

 (10 cones), P. Lambertiana (3 cones), Aiies Morinda (1 cone) 

 P'uius Jeffrcyi (3 cones) W, Arancaria excelsa W, A. imbricata 

 B. Belonging to series \, \, -f-, y\, y'g, etc. Abies Morinda (1 cone), 

 Pinus Lambertiana (1 cone), and Cycus revoliUa (1 male cone) -j^, Pinus 

 Pinaster (3 cones) -f-^, P. Jeffrey i (1 cone) -f^. C. Belonging to series 

 i ^^ |., _3_^ _5_^ gtc. " Zauiia /nrfuracea (1 male cone) f . In another spe- 

 cimen of the same the anthc riferous scales were in alternating whorls of 5. 

 Pinus Pinaster (2 cones) -f-^, P. Lambertiana (I cone). Here the scales 

 at the top and bottom of the cone exhibited a -/-j spiral. The middle of 

 the cone, however, showed 10 secondary spirals running one way and 14 

 the other, being manifestly a bijugate — 5--^(=2\) spiral derived from the 



series |, f, ^, -jV' ^^cf This cone is immature and somewhat irregidar 

 in its development ; and, curiously enough, while the generating spiral 

 above and below runs to the right-hand, the two spirals in the middle run 

 to the left. D. Belonging to series \, J-, -5^, tt» etc. Stangeria para- 

 doxa (male cone) i\. This is doubtless an abnormality, a cone growing 

 upon a plant of the same species in the Edinburgh Botanical Garden ex- 

 hibiting 13 vertical rows, of course resulting from a -^% spiral. Separate 

 allusion mav be made to the cones of Piuus Pinaster, which seem spe- 

 ciallv liable" to variation ; for example, in the museum there are two 

 branches, one with 8 cones, of which there are 6 normal, with /y spiral, 

 one with an ^V' «"<! one with a -^V arrangement ; the other with 5 cones, 

 of which there are 2 normal, two with an Jg-, ai"l one with what seems 



* Trijugate spirals have also been noted as occurring in Pine-cones (L. and A. 

 Bravais, "Sur la Disposition des Feuilles," Ann. des Sc. Kat. 2nd series, vol. vii. 

 p. lOi). And Dr. Dickson has, since the Society's meeting, observed a cone of 

 Abies excelsa, where the arrangement is a trijugate 3-7!^ ( = 6%) spiral. 



t Examples of this series have been observed by Bravais (1. c. p. 93) in Pinus 

 maritima, Dipsaeus, etc. 



