To William Henry Archer   24 April 1874

Mortons Hotel

S Yarra

24/4/74.

You have asked me repeatedly, dear Chev. Archer, to place any material before you, that might be of special microscopic interest.¹ I now send you a few ferns with a view of applying your micrometer to the spores. In the discrimination of the species of fungi and lichens the measurement of the spores has proved of great importance, so also the accurate description of the shape of the spores. For ferns these minute characteristics have as yet not been drawn into use, but I imagine that also among them the size and shape of the spores may be of avail for facilitating distinction and fixing firmer the diagnosis. Perhaps you may wish to take a lead in this new path of enquiry; and now for testing the value of distinctions to be derived from spores I beg to send you a few species all out of the genus Alsophila. Should you find this first trial to be promising, then you might bring the matter before the microscopic Society, so as to evoke aid from many workers. When in first instance the ground work for [the limitation]² of species is laid by us phytographers, we can, [when]³ dealing with thousands of plants not afford time for all such collateral researches, as only subsequently can be carried out by special workers.

To amateurs this kind of work may recommend itself, as the spores are so easily shaken out on the micrometric plate and thus no trouble in preparing the microscopic object does arise.

I will gladly send you more material, should you desire it

Regardfully your

Ferd von Mueller

Alsophila