
THE COMMON HART'S-TONGUE FERN. 151 
stalked divisions like separate young fronds, have been produced 
by the plant gathered at Petersfield.* 
9. sagittato-laceratum (M.). A very elegant form, with dwarfish 
much-frilled fronds, having arrow-shaped basal lobes, and a tendency 
to become multifid at the apex; the divisions of the frilled margins 
are extended into longish acute lobes ; it thus unites the peculiarities 
of crispum (91), sagittifolium (7), and laceratum (145). It was found 
near Whitby in Yorkshire, by Mr. J. Willison. 
10. Monkmanii (M.). This is a dwarfishform, the fronds being 
about eight inches high and nearly two inches wide. They are 
more or less sagittate or hastate at the base, broadest upwards, 
- the margin having a few distant, projecting, pointed lobes, and the 
apex acute or occasionally divided. It was found at Castle Howard, 
near Malton, Yorkshire, by Mr. C. Monkman. Another form 
from the same place closely resembles it, but is somewhat crisped, 
and the base is rather cordate than hastate. 
11. sagittato-eristatum (Claph.). This is a very handsome but 
rather variable form. The fronds are of moderate size, sagittate or 
hastate at the base, the enlarged lobes sometimes directed upwards, 
the margin somewhat wavy and irregular, or here and there bearing 
à few prominent lobes, or branched in the costa; the apex multifid 
and somewhat cristate. The veins are often united near the base. 
It has been found in some abundance by Mr. A. Clapham in 
Raincliff Wood, near Scarborough, Yorkshire. 
* This irregular and abnormal condition of growth, which has appeared in many 
different species, Mr. Wollaston believes to be produced by the puncture of a little 
insect, respecting which he has favoured us with the following memoranda :—“ It 
has long been my opinion that many of the abnormal forms seen among Ferns, and 
more particularly those of Scolopendrium, are caused by a small dipterous insect, 
which deposits its eggs in the cellular tissue between the cuticles of the 
frond. The puncture of, or rather the extraneous matter deposited by, the 
ovipositor, whilst the parts of the frond are in a young undeveloped state, arrests its 
natural development, producing a very perceptible knot-like thickening of the 
tissue, when the frond is held up to the light. It was, I believe, intro- 
duced into my Fernery on a diseased variety of Polypodium Dryopteris, found 
at Ambleside. Tobacco smoke has no effect on it, and it is the greatest 
plague, not even the Thrips excepted, to which Ferns are liable under artificial 
culture, completely destroying their natural characters of growth. I have 
only in one instance been able to detect an empty pupa-case attached to the frond." 
The insect, as we learn from Mr. Westwood, is Sciara minima, but he is doubtful 
as to its being the cause of the mischief. 
ETW ERDE TEE 
. mem ADARE REITER 

