XXXVill INTRODUCTION 



and one-chambered, and contains three lateral rows of ovules. 

 These characters make us again turn to the Polypetalae and, 

 among them, to the Thalami florae. We soon see that the ovary- 

 does not agree with those described in the Tabular View under 

 Orders i — \, or, for that matter, 5 or 6, whilst the numerous 

 stamens at once make us pass over these last two Orders and 

 pause at Order 7, the Reseddcecz, or Mignonette Family. Turning 

 to the fuller description of this group on p. 59, we again find but 

 one British genus, Reseda, containing two wild species. The 

 undivided leaves and four sepals of the plant before us enable us 

 to decide between these two. It is R. Luteola, the Weld or Dyer's 

 Rocket. 



COCHlearia dXnica {Danish Scurvy-grass). 



One more example will suffice. The plant to be examined is a 

 small annual herb growing near the sea or in the m irshes bordering 

 some tidal river. Its leaves are rather fleshy and have no stipules, 

 the lower ones are heart-shaped, and the upper ones, which have 

 short petioles, are deltoid or angular. The white flowers with 

 four distinct green sepals, four white petals and six stamens, of 

 which four are longer than the other two (tetradynamous), after 

 referring us, as before, in succession to Dicotyledons, to Polypetalae, 

 and to Thalamiflorae, cause us, in running through the characters 

 of the Orders, to pause at Order 6, the Cruciferce, or Cabbage 

 Family. This is a large Order containing more than twenty-five 

 genera, so we have to turn to the table of these genera on pp. 

 32 — 34. We may have some little difficulty here ; but, if we find 



