ANONACE^. 251 



shown that this character is at most only sufficient to justify sub- 

 divisions within a genus. The stamens are ahnost always inde- 

 finite in the Anonacece, and it is only since the time of A. de Saint- 

 HiLAiRE that it has been known that Bocatjea may have an andro- 

 ceum of subdefinite elements. The study of B. heterantha has 

 proved to us that the number of stamens may be even quite definite, 

 limited to three or six ; as is also the case with some species of 

 Oro2)haa. But at the same time we have had to unite the American 

 Bocageas and the Asiatic AJphonseas into a single genus. Now the 

 latter often have indefinite stamens. Moreover, when the stamens 

 of the Anonacea are very numerous, they appear, when adult, 

 arranged in a spiral, while in the species of three, six, or nine 

 stamens the existence of triraerous or hexamerous verticils appears 

 quite incontestible. In this res])ect the AnonacecB would resemble 

 the BamuiculacecBy having the pieces of the androceum sometimes 

 arranged in whorls, sometimes in spirals.' 



6. The form of the stamens, the relative size, direction, and position 

 of the anther-cells and connective, especially with regard to the pro- 

 longation of the latter, are of great, though not quite absolute, value 

 in separating genera." There is no reason for hesitating very much 

 before placing a species in one genus rather than in the neighbouring 

 one because its stamens are those of the UoariecB, not of the MiliuseiS, 

 or the reverse. We have seen how Bentham & Hooker go much 

 further, at the very outset relegating all the AmnacecB with stamens 

 of the MiJ'msece to a separate tribe, though the other characters of 

 the fiower are extremely variable in the difierent genera of this tribe. 

 Adopting their standpoint, we should perhaps need to adopt a third 

 type of staminal organization — that so well marked in the group 

 Clathrospermiim of the genus Popoicia. Here the stamens present 

 certain characters of the Uoarica ; for it is impossible to class 

 Popowia in the same division as the Miliusce ; but yet Clathro- 

 spermiim proper has been put in the latter category.'' 



■ The study of development will alone finally ^ We have seen, for instance, that certain 



settle this question. The numerous stamens of Anonas may be considered to possess stamens of 



the Anonacem like those of the Dilleniacea, Bocagea (p. 222), and that in Anaxagorea tne 



might well be originally arranged in bundles. connective often recalls that of several species of 



(For the chief details concerning tlie arrangement Miliusa by its elongated form, and by being flat- 



and the varying number of the pieces of the andro- tened and tajjcring at the apex (p. 207). 



ceuni, see Adansonia, viii, 312-32U.) ^ See Adansonia, viii. 314. 



