Bihliographkal Notices. 291 



the numerous authors who have treated of it as a whole, or who 

 have made additions to our knowledge of its parts. This is fol- 

 lowed by some general observations on the relative importance of 

 the diiferent organs in the formation of genera ; in the course of 

 which are noticed some remarkable deviations from the ordinary 

 rule which attaches the highest value to the direction of the em- 

 bryo \^ith relation to the umbilicus of the seed, and a startling 

 anomaly (not easily reconcileable with the views hitherto enter- 

 tained of the mode in which a change is effected in the relative 

 position of the foramen of the ondum) is for the first time pointed 

 out. ^Ye copy the passage in which this remarkable phasnomenon 

 is described. 



" The direction of Embryo, with relation to the insertion or 

 umbilicus of the seed, appears to be by far the most important 

 character, or that which is best supported by other modifications 

 of structure ; and it is worthy of remark, that in this point the 

 ordinary direction of the embryo in the tribe, namely, the radicle 

 seated at the opposite extremity or apex of the seed, is itself a 

 de\iation from the more usual structm'e of Phsenogamous plants, 

 and an exception not only to the other tribes of Sterculiacece, but 

 to the whole of the natural class Malvacece, to which that order 

 belongs ; and it becomes still more remarkable in regard to the 

 state of the unimpregnated ovulum, which I have some reason to 

 believe is not orthotropous as might be expected, and as it has 

 been described, but apparently anatropous, and that perhaps in 

 the whole tribe. As, however, my observations on this subject 

 are entirely made from the macerated ovaria of di'ied specimens, 

 the statement here made must be received as requiring confirma- 

 tion from the examination of living plants, and of a greater num- 

 ber of species*. 



" From this ordinary direction of embryo in the tribe the de- 

 viations are of two kinds : the first, and no doubt the more im- 

 portant, is that in which the radicle is placed at a point close to 

 the umbilicus, which is the most general structm-e in Phsenoga- 

 mous plants ; but as it never points directly within the umbili- 

 cus, either in this or any other family, I have modified the ex- 

 pression generally employed in such cases. The second deviation 

 is where the umbihcus is placed on or near the middle of the ripe 

 seed with the radicle pointing to its lower extremity ; in other 

 words, where the embryo is parallel to the umbilicus. But this 

 position of umbilicus of the ripe seed does not necessarily imply 



* '* The species of Sterciilia, in which I have found this unexpected po- 

 sition of foramen in the unimpregnated ovuhmi, are fcetida,' guttata, car- 

 tliaginensis, nobilis and angustifolia \ and in the ripe seeds of tragacanth<z, 

 tirens, villosa and qiiadrijida, an indication of a lateral foramen near the 

 base is still visible, but which in fcetida I have not been able to detect." 



