36 9 A. Henfrey on the Higher Cryptogamous Plants. 
supported so strongly as it is by the negative evidence indicated 
under the second head. e 
he positive evidence of the third head is certainly very in- 
sufficient as yet, considering the extreme delicacy of the investi- 
gation. Suminski’s other observations on the details have been 
contested in many particulars; and Mercklin, the only other ob- 
server who asserts that he has seen the spiral filaments within 
the so-called ovules, describes the conditions differently, and states 
that he has only been able to observe them positively there three 
times. At the same time the difficulty of the investigation should 
make us hesitate in attaching too much weight to the failure of 
the other observers in tracing a process of fertilization ; moreover 
it is quite possible that actual entry of the spiral filaments into the 
canal of the ovules or pistillidia is not always, if ever, necessary. 
The facts before us, then, appear to me strong enough to wal- 
rant the adoption of the views propounded by the latest anthors 
on this subject, and the acceptance of the hypothesis of sexuality 
in the Vascular Cryptogams as the most satisfactory explanation 
of the phenomena as yet observed. The question lies now much 
in the same condition as that of the sexuality of flowering plants 
before the actual contact of the pollen-tubes with the ovules had 
been satisfactorily demonstrated. teh 
urther arguments may be adduced from grounds lying out of 
the preceding statements, viz. 1. The late discovery of two forms 
of organs in the Algz, Lichens and Fungi, which, although im- 
perfect at present, lead to the expectation that the analogues of 
the antheridia and _pistillidia of the Mosses, so long known, will 
be found in all Cryptogamous plants. 2. The analogies between 
the processes of animal and vegetable reproduction which a 
to be offered by these new views of the nature of the phenomena 
inthe Vascular Cryptogams. 'To this last argument I shall merely 
allude, as it may be considered to lie beyond the special provinee 
of the vegetable physiologist; yet when we recollect the impet> 
ceptible character of the gradations of the lower forms of the two 
kingdoms, there seems far sounder ground than is allowed by 
Schleiden for arguing from apparent analogies between the phe 
nomena occurring in the two great kingdoms of nature. cs 
Under the second point of view mentioned above, the facts of 
structure may soow be disposed of, so far as the analogies of form 
“ovules” of the Ferns, Equisetacee, Lycopodiacee, Isoétace®, 
. ; 1M general structure and in the presen of the 
central large cell from which the new form of structure originates- 
