292 OBSERVATIONS ON PLANTS 



reference to the axis of the spike, in Polygalese, namely, 

 the fifth segment of the calyx being posterior or superior 

 and the fifth petal anterior or inferior, is the usual relation 

 in families the division of whose flower is quinary. This 

 relation is in some cases inverted ; one example of which I 

 have formerly pointed out in Lobeliacese,^ as I proposed to 

 limit it, and a similar inversion exists in Leguminosae. 

 But this class also deviates from the more general arrange- 

 ment of the parts of the flower with regard to each other. 

 That arrangement consists, as I have long since remarked,^ 

 in the regular alternation of the divisions of the proximate 

 organs of the complete flower. To this arrangement, in- 

 deed, many exceptions are well known ; and M. De Can- 

 dolle has given a table of all the possible deviations, but 

 without stating how many of these have actually been ob- 

 served.* 



In Leguminosse the deviation from the assumed regular 

 arrangement consists in the single pistillum being placed 

 opposite to the lower or anterior segment of the calyx. 



In these two characters, namely, the relation of the calyx 

 and corolla both to the simple pistillum and to the axis of 

 the spike or to the bractea, Leguminosse differ from Rosacese 

 in which the more usual arrangements are found. 



But in those Rosaceae in which the pistillum is solitary 

 and placed within the anterior petal, its relation to the 

 axis of the spike is the same as that of Leguminosse, in 

 which it is within the anterior division of the calyx. And in 

 all families, whether dicotyledonous or monocotyledonous, 

 this, I believe, is uniformly the position of the simple solitary 

 pistillum with regard to the spike or bractea. 



The frequent reduction of Pistilla, in plants having the 

 other parts of the flower complete in number, must have 

 been generally remarked. But the order in which these 

 abstractions of pistilla take place, or the relations of the re- 

 duced series to the other parts of the flower, have, as far as 

 I know, never yet been particularly attended to. It will 

 probably appear singular that the observation of these 



1 Flinders' sAustr.'i, p. i%Q. {Jnle,p.3'i.) 



" Prodr. Flor. Nov. HoU. 1, f). 558. ^ y^^^^, ^i^^^^ ^^_ g, p. 183. 



