88 Mr. Brown's Observations on (lie 



in the passage referred to observed that the valvular and indupli- 

 cate modes of testivation easily pass into each other, merely by 

 an addition or abstraction of the elevated margins of the laciniae : 

 instances of their abstraction, and of the consequent conversion 

 of the induplicate into the valvular mode, occur in several Good- 

 enoviae, and in some Convolvulaceae and Solanaceae ; while 

 Chuqidraga and Conjmbium are examples of their addition in an 

 order where they are generally wanting. 



My third remark is entirely borrowed from Schkuhr*, who 

 states that in all Cichoraceee or Ligulataj the pollen is angular, 

 and that in Corijmbiferce and Carduacea, or in all tubular florets, 

 it is spherical or oval. 



All the figures which this author has given of pollen in Cicho- 

 raceac represent it as a regular icosahedron, except that of Gero- 

 pogoii glabrum, which is a dodecahedron. I believe neither of 

 these forms of pollen has been observed in any other family of 

 plants. 



A fourth remark on Compositae 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. Cassini regards as 

 their original position. 



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 

 fj'th remark, which relates to the internal structure of the Ova- 



* Botauisches Handbuch 3. p. 8. 



rium 



