92 ORGANOGRAPHY. BOOK I< 



The scales of the fruit of Coniferous plants are nothing but 

 pistillary leaves, which do not form, like the floral envelopes 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 atten- 

 tively 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 ap- 

 pear to be upon the same plane; but a more attentive examin- 

 ation 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 disposed 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 ; 2d, As to their in- 

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

 their axis ; 3d, As to their total number, and their arrange- 

 ment round the common axis, which constitutes their co-ordi- 

 nation. 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 na- 

 ture. 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 dis- 

 coverable in the arrangement of their scales, and that there 

 invariably exists between these spires certain arithmetical 

 relations, which are the expression of the various combina- 

 tions of a certain number of elements, disposed in a regular 

 manner. All the spires depend upon the position of a funda- 

 mental series, from which the others are deviations. The 

 nature of the fundamental series is expressed by a fraction, of 

 which the numerator indicates the whole number of turns 

 required to complete one spire, and the denominator the 



