136 Proceedings of the 



stamina, and frequent in the ovaries, the number of which is often 

 less than that of the other parts, and the unequal developement of 

 which may be constantly observed both during and after its progress 

 towards maturity. Thus the passage from regularity to irregularity in. 

 flowers becomes insensibly established. These irregularities could 

 hardly be explained on the supposition of the parts being exact ver- 

 ticilli, and therefore placed in conditions equally favourable to 

 developement. In fact, no examples of irregularity are found in 

 flowers of the valvulary or twisted efflorescence, which invariably 

 indicates the disposition of the parts in verticilli. In a quin- 

 cunx, on the contrary, it is clear that the upper parts are placed in a 

 situation more unfavourable to their developement. This is espe- 

 cially true with respect to the ovaries, because the action resulting 

 from the relative situation of the parts has fuller force from there 

 being no quincunx above it. This tendency to irregularity in the 

 flowers in which the parts are disposed in quincurices, is not much 

 observed when the two halves of the conic spindle are placed 

 in equally favourable conditions, which is the case when the axis of 

 this cone has a direction according to the elongation of the peduncle. 

 But when the flower rests on the peduncle by an oblique base, one of 

 its halves is situated higher than the other with relation to the axis 

 of the plant, and is therefore in a situation more likely to produce 

 abortions. This obliquity of the base exists in the majority of irre- 

 gular flowers, particularly in those in which the inequality of the two 

 halves is very decided, and which are called didynamia. These 

 causes of irregularity will be much greater, if, instead of supposing 

 the spiral constructed on the circle which forms the base of the conic 

 spindle, we suppose it constructed on a section which is oblique to 

 the axis, that is to say, on an ellipsis. In this case, every spiral turn 

 ascending and descending alternately as respects the axis, the series 

 of the insertions will no longer have an exact reference to their 

 heights, and thence will result an order apparently differing from the 

 quincunx. The calyx of the antirrhinum majits, the insertion 

 of which is extremely oblique, affords an example of this. M. Jussieu, 

 having thus laid down his position, proceeds to exemplify it by nu- 

 merous examples, illustrated by plates ; but it is unnecessary to cite 

 them here, as the above explanation of his theory will be sufficient to 

 enable our botanical readers to verify or refute his ingenious hypo- 

 thesis. We shall take care to make known the report which will be 

 made to the Academy on the subject. 



CHEMISTRY. 



Perchloric Acid Per chlorates a test for Potassa and Soda. 

 On the 25th of April, M. Serullas communicated the particulars of 

 some experiments which he had recently made on this acid, con- 

 sidered as a re-agent, by means of which to distinguish and separate 

 soda from potash, either alone or combined with other acids. He 

 led to make these experiments from observing the great differ- 



