28 ^ MEMORANDA. 
mena connected with the subject. Several curious questions have to be con- 
aidered in relation to double flowers. Do not they often begin to bloom 
earlier than the single states of the same species ? If the common double 
DafibdU of every garden be Narcissus Pseudo-fjarcissus, it supplies a ready 
example. Have double flowers more or less odour than tlie single states of the 
same species ? What has been observed in reference to their capacity for re- 
lapse ? I have many memoranda upon these and collateral points, and pro- 
pose to collect them. I believe also that I can add slightly to the general 
list. 
I am, etc., 
Leo H, Geikdon. 
85j Bumford Street^ Manchester^ Nov, 24, 1864. 
[The considerations liere urged upon my attention were not overlooked by 
me, but I stated that I had at present no time to work out the subject to its 
legitimate conclusion, and published my list of double flowers merely to place 
it at the service of those who had. Nevertheless, I am much obliged to the 
author for his remarks ; they will be useful to aU those who may take an interest 
in the subject. — Editok.] 
MEMOEANDA. 
Jgaricus cartilagineus, Bull. A specimen of this fimgus was lafely sent to 
the herbarium of the British Museum, which was found growing below the 
pavement in Groswell Koad, London. Its mycelium was developed into an 
enormous spongy mass, and in pushing up its many -headed pileus, it raised a 
stone weighing two hundredweight, and measuring 4 feet 1 inch by 2 feet 1 
inch. Some years ago, the town of Basingstoke had to be repaved, on account 
of the rapid growth of large Toadstools below the pavement. The damage in 
Go5vvell Road has however been confined as yet to the work of this one plant. 
On the Sxsxematic Position of Hymexophtlue^. — Mettenius, in his 
recent publication on * HymenophyllesB * (Leipzig, 1864), arrives, after a care- 
ful esamination of this interesting group of Ferns, at the conclusion that "on 
account of the numerous peculiarities of Hymenoplitfllum and Trichomanes ^ 
it would appear natural to remove them from the position they have hitherto 
held between the Cyatheace<B and GleicheniecB, and place them before the 
P^il^jpodiece^ i. e, assign to them the lowest rank amongst the Ferns ; in their 
downward relationship they would border on Mosses, especially the Sphagneoe^ 
with which they agree in then' development and still more ia the prothallium, 
at the same time differing very widely, and being very far removed in these 
points from the Ophioglossea" The considerations wliich Mettenius here 
advances in 1864 determined the elder Reichenbach, as early as 1828 (* Con- 
spectus Begni Yegetabilis,* p. 37), to regard the St/menophgllece as the 
lowest group of the Ferns ; and in his ' Repertorium Herbarii, sive T^omen- 
clator Gtenerura Plantarum' (Dresden and Leipzig, 1841), he placed them in 
that position, removing from them the CyatheacecB as a higher group by 
