186 Mr. J. Miers on the germs Schwenkia. 



always seen between the divisions of the border, and which he 

 showed to be the true segments, while the others were mere 

 appendiciform expansions, and under this ingenious point of 

 view, he was enabled to reconcile its structure with the opinions 

 of Jussieu : following the example of Kunth, he therefore ar- 

 ranged both Schwenkia and Browallia in the Scrophulariaceee, 

 among his tribe of the Salpiglossidecs (De Cand. Prodr. x. p. 122). 

 Martins suggested its affinity with the Acanthacem, a view not 

 confirmed by other botanists, and quite unsupported by facts. 

 It is now fourtyears since I first explained in what respects this 

 genus differs from Browallia and other genera of the Salpiylos- 

 sidece [huj. op. iii. 177), and I indicated the circumstances that, 

 in my opinion, point to its nearer affinity to Fabiana, in the 

 Solanacece. This genus forms one of those instances, in which 

 it is difficult to determine, under the ordinary interpretation of 

 the respective ordinal characters, whether it belongs to Solanacece 

 or Scrophulariacece. In order to obviate uncertainty in similar 

 cases, I endeavoured to show {loc. cit. p. 163), and again lately 

 [huj. vol. p. 6), how by separating certain anomalous genera of 

 these two orders, marked by peculiar characters, into a separate 

 family, a prominent and unerring line of demarcation may be 

 established between the foi-mer, — a difficulty that has hitherto 

 puzzled every botanist. Under this test, Schwenkia must be 

 referred to the Solanacece, on account of the decidedly valvate 

 {estivation of the corolla, as I shall presently endeavour to show. 

 It may be urged, that in Schwenkia the total number of lobes 

 in the border being generally more than five, and the suppression 

 or diminution of some of these and of the stamens being of fre- 

 quent occurrence, are features quite foreign to the Solanacece. 

 But in Hebecladus and Dunalia we meet with five intermediate 

 teeth between the lobes of the border, and in Nectouxia, an 

 annular 10-toothed ring is placed in the mouth of the coi'olla, 

 within the line of origin of the five segments, forming thus a 

 corona, closely analogous in its nature to those more expanded 

 petaloid segments which Mr. Bentham desci'ibes as appendi- 

 ciform processes in Schwenkia. In this genus the stamens are 

 always five in number, and are situated below the middle or near 

 the base of the tube of the corolla ; of these, two, or sometimes 

 four, are antheriferous and reach the mouth of the tube, while 

 three, two, or one, are occasionally sterile or anautherous, the 

 filaments in such case being sometimes short and rudimentary. 

 In many Solanaceous plants there is often a diff'erence in the size 

 of the stamens, and this becomes a constant feature of the section 

 Nycterium of the genus Solanum, where three of them are always 

 considerably larger than the two others, which are sometimes 

 almost sterile. The suppression of some of the anthers, and of 



