and on various Plants related to them. 343 



Obs. I. — By this singular plant I would wish to commemorate the late 

 Mr. Thomas Smith, the discoverer of one of the most important points of 

 vegetable structure, on which a very general rule has been founded. To his 

 great merits the following quotation from Mr. Robert Brown's remarks on 

 Kingia bears the most satisfactory testimony : — " I was aware of the exist- 

 ence, in several plants, of a foramen in the coats of the ovuluin, always distinct 

 from, and in some cases diametrically opposite to, the external umbilicus, and 

 which I had- in no instance found cohering either directly with the parietes of 

 the ovarium or with any process derived from them. But as I was then 

 unable to detect this foramen in many of the plants which I had examined, I 

 did not attach sufficient importance to it; and in judging of the direction of 

 the embryo, entirely depended on ascertaining the apex of the nucleus, either 

 directly by dissection, or indirectly from the vascular cord of the outer mem- 

 brane ; the termination of this cord affording a sure indication of the origin 

 of the inner membrane, and consequently of the base of the nucleus, the 

 position of whose apex is therefore readily determined. In this state of my 

 knowledge the subject was taken up in 1818 by my lamented friend the late 

 Mr. Thomas Smith, who, eminently qualified for an investigation where minute, 

 accuracy and great experience in microscopical observation were necessary, 

 succeeded in ascertaining the very general existence of the foramen in the 

 membranes of the ovulum. But as the foramina in these membranes invari- 

 ably, correspond with each other and with the apex of the nucleus, a test of 

 the direction of the future embryo was consequently found nearly as universal 

 and more obvious than that which I had previously employed." — Appendix to 

 Capt. P. P. King's Coasts of Australia, ii. p. 541 . 



foliorum. SplcK bracteatae, densifloroe. Flores minuti, pallid^ brunnei. Capsula ecristata. Semina 

 albuminosa. Embryo dicotyledoneus. 



The Burmannia belongs to a form not uncommon in some parts of India characterized by an absence 

 of ordinary leaves and green colour, small stature and few flowers, which are either white or blue. It 

 would appear to approach the Gonyanthes of Blume. While Salomonia aphylla is curious as an instance 

 of specific parasitism on roots, unaccompanied by the ordinary modification of form of the embryo, 

 Burmannia is perhaps equally curious for exhibiting instances of the form of embryo usually associated 

 with parasitism on roots, in connexion, in one forro, with apparent parasitical habits, in the other mth 

 leaves apparently of ordinary structure and function. 



VOL. XIX. 2 z 



