STRUCTURE.] SPIEAL ARE ANGEMENT BRAUN. 245 



are determined. The original appeared in the Nova Act a of 

 the Imperial Academy Naturae Curiosorum ; and a very full 

 abstract of it has been given by Martins, in the first volume 

 of the Archives de Botanique, from which I borrow what 

 follows : 



"The scales of the fruit of Coniferous plants are nothing 

 but carpellary leaves, which do not form, like the floral enve- 

 lopes of other plants, a complete cavity surrounding the 

 sexual organs on all sides, but which are slightly concave, 

 and protect them on one side only. This point admitted, if 

 we consider attentively the cone of a Pine, or of a Spruce 

 Fir, we are at once led to inquire whether the scales are 

 arranged in spires or in whorls. Breaking through its 

 middle a cone of Pinus Picea (Silver Fir), we remark three 

 scales, which at first sight appear to be upon the same plane ; 

 but a more attentive examination shows that they really 

 originate at different heights, and moreover, that they are 

 not placed at equal distances from each other; so that 

 we cannot consider them a whorl, but only a portion of a 

 very close spiral. But, considering the external surface of 

 the cone viewed as a whole, we find that the scales are dis- 

 posed in oblique lines, which may be studied 1. As to their 

 composition, or the number of scales requisite to form one 

 complete turn of the spire ; 2nd. As to their inclination, or 

 the angle, more or less open, which they form with their 

 axis ; 3d. As to their total number, and their arrangement 

 round the common axis, which constitutes their co-ordination. 

 Finally, we may endeavour to ascertain whether the spires 

 turn from right to left, or vice versa. 



He then proceeds to show, that the spiral arrangement is 

 not only universal, but subject to laws of a very precise 

 nature. The evidence upon which this is founded is long 

 and ingenious, but would be unintelligible without the plates 

 which illustrate it. I must, therefore, content myself with 

 mentioning the results. Setting out from the Pine cone 

 above referred to, he found that several series of spires are 

 discoverable in the arrangement of their scales, and that 

 there invariably exists between these spires certain arith- 



