330 



on very hot soil together with the previous species, foUows 

 in our country remarkably the big rivers, the river-mouths 

 of the province or Zeeland, the ancient Rhine-bed of 

 Van Eeden and the river Vecht; in Belgium it is rare 

 and nearly confined to the valley of the Meuse; 



Erucastrum Pollichii Sch. et Sp. is a common species 

 along our big rivers, also along the ancient river-beds of 

 the Rhine, but besides it also has been found on railway- 

 embankments, which may be after ail easily understood ; 

 in Belgium it is extremely rare and has only been recorded 

 from a few places as an alien ; 



Dianthus deltoïdes L., specially common along the river- 

 beds of the Ysel and the river Vecht in the province of 

 Overijsel, has however also been recorded from the south 

 of Limburg, the valley of the river Eem and the neigh- 

 bourhood of the ancient Rhine-mouth near Katwijk ; further 

 from the east of the province of Groningen (near the 

 Eems !), the isle of Walcheren and a few other places ; 

 in Belgium it is chiefly confined to the régions of the 

 Meuse and there still it is rare; 



Galium verum L., the least important species to our 

 purpose, may be said to grow chiefly along our big 

 rivers, but is also found in many places far away from 

 them, on railway-embankments e.g. and along the whole 

 coast; it is widely spread in Belgium. 



Knowing that it was just the oak-age, which ofîered a 

 last chance to the typical plants of the river-valleys to 

 penetrate into England, we are now of course anxious to 

 know, which is the distribution of the above-named species 

 in England. My communications are based hère on the 

 data, which Prof. Tansley has been kind enough to give 

 me. Galium verum is as common in England as it is in 

 our country and Belgium ; therefore it is of no further 

 importance to our purpose. Dianthus deltoides too is 

 widely spread in Great Britain, with the exception of 



