66 A CONTEIBTJTION TO, ETC. 



and at first, I felt some difficulty in distinguishing a variety of JV. 

 propinquum, which is reported to have proliferous fronds, from 

 another fern, also gathered by Mr. Macgillivray (Polypodium pro- 

 liferum), to which we shall allude hereafter. At first sight, there 

 is a great resemblance between the two ferns, both in the shape 

 of the fronds and in the velning, but the position of the sori, as 

 well as the absence of an indusium, must cause them to be placed 

 under different genera. Mr. Macgillivray, who was a very accurate 

 observer, called my attention to these particulars, and I felt much 

 obliged to him for enabling me to form a satisfactory opinion as 

 to the specific difference of these ferns. 



I believe that JV. molle is the only 'one of the three Neplirodia, 

 which seem so intimately connected with each other, that is 

 found near Sydney, but this fern has a very wide range, as Mrs. 

 Forde has recently collected it on the cliffs of the Murray near 

 Blanch Town. With respect to N. decompositim, the frond of 

 which is much more divided than any of the preceding, I confess 

 that I feel considerable difficulty, as Hooker has united so many 

 forms that are generally regarded as distinct, amongst which are 

 N. microsorum, N. glabellum, Lastrea acuminata, and N. tenerum. It 

 would be difficult for any one, who has not had an opportunity of 

 examining all the intermediate forms of this variable fern, to ar- 

 rive at the same conclusion as the venerable Hooker. In the 

 opinion of several intelligent observers, who have forwarded to 

 me specimens representing the most marked varieties of the 

 species, there seems so wide a difference between the type of the 

 species and Lastrea acuminata, that such a variation is regarded 

 as something more than an accidental deviation. I have seen 

 specimens of this fern from the neighbourhood of Parramatta, 

 the gullies of the county of Camden, the Blue Mountains, the 

 Macleay, and the Clarence ; and unless I had the authority of 

 botanists so distinguished as Sir W. Hooker and Dr. E. Mueller 

 for believing that the varying forms belong to one and the same 

 species, I should be inclined to an opposite opinion. As, how- 

 ever, I have had occasion to remark previously, in reference to 

 another species, there may be so gradual a transition from one 

 form to another, that we must either adopt the views of these 

 eminent men, and make one species, or consider every variety a 

 distinct species, which, I suppose, few who have studied the sub* 



