264 HOFMEISTER, ON 



ment in question assumes a very different aspect, if the 

 view suggested by Pringsheim ( ( Bot. Zeit.,' 1853, p. 

 609), and supported by Irmisch (' Bot. Zeit./ 1858, p. 

 492) be adopted. According to this view (which I con- 

 sider correct), all normal ramification rests upon bifurca- 

 tion of the end of the stem above the youngest leaf of the 

 bud, the result of which usually is, that one fork of the 

 branch developes itself more vigorously than the other, and 

 forms the prolongation of the principal axis, whilst the 

 other which is less strongly developed and is displaced side- 

 ways, forms a lateral branch. It is hardly necessary 

 to remark that the existence of a definite relation between 

 the positions of the branches and the leaves is entirely recon- 

 cileable with this view. No supporter of it has denied 

 the fact. In phamogams the less-developed branch, — 

 which, in consequence of its inferiority of development 

 becomes a lateral branch of the more vigorously developed 

 one, — is usually inserted in the axil of the next lower 

 leaf, but this circumstance is of little importance, inasmuch 

 as no causal connexion is anywhere proved to exist, or as 

 far as we know even suspected, between the anatomical rela- 

 tions of the axil of the leaf and the insertion of the lateral 

 branch. Nothing is more certain than that the rudiment 

 of the lateral branch in all cases hitherto examined is formed 

 immediately after the commencement of the formation of 

 the phyllophore, and that the next higher leaf in a 

 vertical direction is first formed at a much later period. The 

 essential difference between the existing opinions relates 

 therefore only to the question whether the dichotomous 

 ramification of fern-stems and the formation of buds at the 

 base of the stipes of ferns are processes of a similar 

 nature; whether both stand in the same relation to the 

 principal axis as the axillary buds of phsenogams. Obser- 

 vation gives immediately a negative answer. The adventi- 

 tious buds which are situated upon the back of the stipes 

 of Asjpidium filix-mas, as well as those which are inserted 

 lower down in Pteris aquilina and Struthiopteris, are not 

 formed until the frond has reached a high degree of deve- 

 lopment, a fact quite at variance with the mode of produc- 

 tion of the axile buds of monocotyleclonous or clicoty- 



