930 



of an incipient caudex. When it is matured according to some one 

 of the forms it assumes in different species, a root is protruded from 

 one side of it, and soon after a small gyrate frond emerges from its 

 summit, which, when developed, occupies the edge of the cellular 

 knot, having the base of its stipe placed directly over the base of the 

 radicle. The last immediately descends into the earth, while the 

 former, rising from under the primary frond, opens out into a small 

 simple or lobed leaflet. When this is matured another is sent out, 

 and the same process is repeated, a new root being in general added 

 with each successive frond. The cellular mass in the meantime ac- 

 cumulates, and is gradually converted into a central caudex. The 

 primary frond having completed its office withers and decays, while 

 the characters of the perfect fern become more and more apparent, 

 as one frond succeeds to another." — p. 335. 



It is no part of our design to investigate with a view to criticism 

 these preliminary quotations : our readers will not, therefore, draw 

 the conclusion that we assent to Mr. Henderson's suggestions because 

 we make no attempt to refute them : we wish merely to trace the his- 

 tory of these observations up to the present time ; and, as we have 

 already stated, shall express our own views hereafter. 



On the continent the subject has received more careful investigation 

 than with us. Agardh has figured the pro-embryo and the develop- 

 ment of the first circinate frond more faithfully than either of the au- 

 thors we have cited (see Lehrbuch der Botanik, pi. 3, figs. 40 — 42). 



We now arrive at that discovery which originates the question to 

 be considered. In the year 1844, Nageli found on the under surface 

 of the pro-embryo of ferns bodies which he considered absolutely 

 analogous to what are termed the antheridia of the Musci, Hepaticae 

 and Characeee. In the ' Zeitschrift fur Wissenschaftliche Botanik 

 von M. J. Schleiden und Carl Nageli,' published in Zurich, he de- 

 scribed these organs with great minuteness and accuracy ; but his 

 conclusions differ from those of the author whose work is the subject 

 of these remarks, inasmuch as he regarded the larger organs or pistil- 

 lidia of Suminski to be absolutely identical with the antheridia, but 

 to have attained a more advanced stage, and exhibited a more perfect 

 development. Suminski, criticising this view, asserts that " Nageli 

 was guided by a false principle in his researches, since the bodies in 

 question are readily distinguishable as two separate classes of organs, 

 whether we regard their actual structure or the physiological func- 

 tions they are destined to perform." The soundness of this criticism 

 we again leave to the judgment of others, and proceed to a literal 



