BERKELEY, ON CRYPTOGAMIC BOTANY. 179 
under his eyes, if he possesses proper powers of manipulation, which will 
searcely ever be the case with Pheaogams, if the parts be freed ever so 
neatly from the surrounding tissues. Nay, the examination of the develop- 
ment of cells in such genera as Hematococcus and Gleocapsa will help even 
the Zoologist, for nothing ean be more close than the mode of development 
in these, and of the vitellus in the eggs of certain Mollusca. 
“The bodies, indeed, which are so much alike, or in other words, are 
homologous, identical, that is, in structure and genesis, though not in func- 
tion, may not always be of equal value; but the student will learn as much, 
perhaps, from the observance of their differences, as if they were in every 
respect perfectly accordant.” 
Some of the earlier of these remarks may perhaps be 
regarded as seyere, but they are the result of the observation 
and reflection of one who has entitled himself to be regarded 
as a master of the subject on which he writes, and must be 
received with all due respect. The following passage is on 
a subject which has recently undergone discussion in our 
pages, and will be read with interest. 
“Nor will a few words on this subject of species be completely out of 
place, though we have incidentally touched on it before. It is one which 
the cryptogamic student will meet with at every turn. It is a common 
opinion that cryptogamic species are so variable, that it is impossible to cir- 
cumscribe them with specific characters; and, to be studied with certainty, 
they must be studied in the herbarium. ‘The practised eye will there detect 
similitudes between widely different forms which no definition could convey. 
Now there is certainly much truth in this notion, but more perhaps, from 
the wrong conception of authors than from the intrinsic difficulty of the 
case. So long as essential characters are neglected, and fleeting external 
characters put in their place, difficulty must needs exist, and the student 
will never be certain that he has come to a correct decision till he has seen 
an authentic specimen, or compared his own decision with that of other 
botanists as manifested in extensive herbariums. A state of uncertainty is 
always one of more or less pain, and the temptation to a solution of the dif- 
ficulty by the supposition that he has made some new discovery, will often 
present such attractions as to prove insurmountable. Nor will he find it 
possible, without that mental discipline which arises from a patient study of 
every detail of structure, and of the various shapes which organs may assume 
under different circumstances. Without such discipline, like certain German 
authors of some repute amongst persons uninstructed in the subjects they 
profess to handle, he will propose a new name for every difference, even such 
as are manifestly merely temporal and accidental, and, on the contrary, he 
will unite whole groups which belong to entirely different categories. It 
would be easy to point out glaring examples, both amongst algologists and 
mycologists. One of the worst amongst Phenogamists, perhaps, is the 
erection of that state of the inflorescence of several species of Cissws, in 
which the peduncles are deformed by the presence of an internal parasite 
(Puccinia incarcerata, Lév.), into a distinct genus of Phenogams; though 
this is not worse than referring the same Alga received from different 
sources to two or more distinct genera, and that not among the lower or 
more obscure species, where there might be some excuse for such a pro- 
ceeding, or the association of plants so totally different, as Puccinia and 
Trichothecium. Nor is the correct appreciation of species of so little 
consequence as is sometimes vainly supposed. ‘The only way in which 
