4. CRUCIFER^. 161 



and it has never been sent to me under name of ' Napus,' 

 except fi-om the " Castle Rock," at Edinburgh. See the 

 remarks under B. campestris. 



116. SiNAPIS ARVENSIS, Limi. 



Ai'ea, general. 



South limit in Cornwall, Isle of Wight, Kent. 



North limit in Shetland, Orkney, Hebrides. 



Estimate of provinces 18. Estimate of counties 82. 



Latitude 50 — 61. British type of distribution. 



Agrarian region. Inferagrarian — Superagi'arian zones. 



Descends to the coast level, in the Peninsula. 



Ascends to 400 yards, in the East Highlands. 



Range of mean annual temperature 52 — 43. 



Native. Agrestal and Septal. Abundantly common as 

 this plant is with us, and locating itself on hedge-banks as 

 well as in cultivated ground, it is still, perhaps, originally 

 an agiicultural introduction. I observed it in the fields 

 about Castletown and Dalwhinnie, 350 and 400 yards ; but 

 whatever we may say about the lower and southern distri- 

 bution, the ascent to that elevation, in the Highlands, is 

 natural only through the aid of man, who prepares the 

 gi'ound, and probably carries thither the seeds. 



117. SiNAPis ALBA, Linn. -^ ^''^ ///-/■ O'S'f^. 



Aiea 12 3 45*78$ .^''ll * 13 14 15 16 17 18. 



South limit in Devon, Isle of Wight, Kent. 



North limit in Hebrides and Ross-shire. 



Estimate of provinces 18. Estimate of counties 60. 



Latitude 50 — 59. British type of distribution. 



