88 Mr. Brown’s Observations on the 
in the passage referred to observed that the valvular and indupli- 
cate modes of æstivation easily pass into each other, merely by 
an addition or abstraction of the elevated margins of the laciniz : 
instances of their abstraction, and of the consequent conversion 
of the induplicate into the valvular mode, occur in several Good- 
enoviæ, and in some Convolvulaceæ and Solanaceæ ; while 
Chuquiraga and Corymbium are examples of their addition i in an 
order where they are generally wanting. | 
My third remark is entirely borrowed from Schkuhr*, who 
states that in all Cichoracee or Ligulate the pollen is angular, 
and that in Corymbifere and Carduacee, or in all tubular florets, 
it is spherical or oval. 
All the figures which this author has given of pollen in Giit 
racez represent it as a regular icosahedron, except that of Gero- 
pogon glabrum, which is a dodecahedron. I believe neither of 
these forms of — has been observed in à mans — » 
plants. 
A fourth remark on — I do not offer with absolute 
confidence, as it is opposed to the statement of M. Cassini, on 
whose general accuracy I have great reliance. It relates to the 
disposition of the branches of the style or stigmata, which accord- 
ing to M. Cassini are lateral, or right and left with relation to the 
axis of the common receptacle ; whereas; 1 consider them as.an- 
terior and posterior, though in many cases by a slight degree of 
twisting in the style they acquire what M. past regards as 
their original position. os 
This may seem a point of very little consequence to establish. 
Independent however of the necessity of minute accuracy in 
every case, it appears to me to have some connexion with my 
fifth remark, which relates to the internal structure of the Ova- 
* Botanisches Handbuch 3, p. 8. 
rium 
