104 THOMAS RICHARD ARCHER BRIGGS. 
nature of the rock, and not its composition (in other words, its 
elon rather than. its chemical pee oes akes the 
plant avoid it. The power of a certain kind o in ibescbing: 
ais or parting with moisture ee eem se have much 
more to do with determining the character of “the vegetation on it 
than has 7 chemical composition.’ 
ollowing extract is from the second of these lectures :— 
‘¢ Pimpinella magna L. affords a rem ve instance of what 
appears arbitrary range in on and Il... . Around the 
Pp in 
northerly direction, it becomes uncommon between Tamerton 
chee and Buckland Monachorum, and I have not met with it*in 
any part of Devon north of this latter parish. Hast of Plymouth it 
is aaaiek on to at least the portion of the Erme basin lying south 
of Ivybridge. .... Across the Tamar, and so in EK. Cornwall, it 
occurs in certain spots in the parishes of Maker, Rame, Antony, 
St. Johns and St. Stephens, also in the grounds at Pentillie; but 
beyond these parts I have never come across it in the whole county 
of Cornwall, though Watson does give it as a West Cornwall species 
on the authority of Dr. Oliver. It is unrecorded for N. ste and 
the whole county of Somerset, but re-appears in many plac the 
kingdom, reaching Norfolk and West Perth, so that oieate” cannot 
have anything to F with its circumscribed range in the south-west. 
In = ns so alg Plymouth it seems an increasing rather than 
decreasing spec It seeds abundantly, and has a remarkable 
ace ol quickly eendtiig up flower-stems when the earlier ones are 
cut off by the hedger’s hook; these in mild seasons will sometimes 
e in pile so late as November or December. It might be yet 
— lage g with us if a small lepidopterous larva did not form a 
of the umbels, by drawing their unopened flower-buds 
ieyethae fe silky threads, to find within a dwelling and supply of 
food at the same dime.” 
Tt toa be tedious to enumerate even the chief of his very 
numerous discoveries in local botany, as announced from time to 
time in the Botanical Exchange | ree Reports and in the several 
volumes of this Journal; but a of the species and chief varieties 
added to the Pio of the British Toles through his researches would 
seem not out of place here. I am much indebted, as primarily, to 
Colonel Briggs for much varied scfoeinptitin, so also to Messrs. 
Arthur - Bagnall for many notes and verifications 
of references bearing on these from books not in m lib 
st ie and varieties are, so far as I have been able to ascertain, 
as 
Heenan undulatum Schousb. Eiourn, Bot. 1864, Be 
~~. aa Focke (Fl. Plym. 111, under /issus; Journ = 1890, 
