OBSERVATIONS ON HOLL’S LIST. 23 
afforded facilities to my researches, incomparably greater than 
any casual or temporary visitor can possess. Mr. Holl had 
not only to contend with the common disadvantages of a mere 
visitor, but to struggle with other peculiar and most oppressive 
difficulties; and I am truly gratified to find that, in the face 
of obstacles which few men could have surmounted, he has 
been able to produce a list so highly creditable to his zeal, in- 
dustry, and botanical acquirements. 
Such, indeed, is the general interest of his publication, that 
I am unwilling the little inaccuracies and mistakes it appears 
to me to contain, should pass unrectified. The length of my 
residence in Madera having afforded me opportunities which 
Mr. Höll could not possibly enjoy, he will, I am sure, be the 
last person to take umbrage at any emendations proposed in 
a spirit of regard and respect to his merits, and out of a mere 
love of truth and accuracy. 
To yourself, my dear Sir, I make no apology; for I feel 
assured that the last-mentioned consideration, be the subject 
so trifling, will vindicate the attempt, and obtain your con- 
currence and approbation. I shall therefore commence, without 
longer preface, my remarks on those points which, on a necessa- 
rily hasty perusal of the List, have principally seemed to demand 
explanation or correction. I am obliged, from want of time 
for making the necessary comparisons, to omit the greater 
part of the Cryptogamia for the present, and, therefore, begin 
at a point from which a coincidence of subject-matter com- 
mences between Mr, Holl’s List and the first part of my Pri- 
mitie, published in the ** Transactions of the Cambridge Philo- 
sophical Society,” namely, the 
FILICES. 
* Lycopodium Selago, Linn.”—This is L, suberectum, nob. 
in C.F. S.Tr. 
* Ophioglossum Lusitanicum, Linn.,” is extremely rare and 
local. Ihave only found it in a single spot at the western 
point of the Island (Porta de Pargo), though growing there 
abundantly in a small piece of wet splashy ground, amongst 
