THE HIGHER CRYPTOGAMIA. 245 



pmictum vegetationis. The multiplication of shoots by 

 means of adventitious buds is proportionably more frequent. 

 These buds always originate on the back of the stipes, at 

 the place where the protuberant swelling of the latter passes 

 off into the more slender upper portion. After the removal 

 from the stipes of the thick covering of scales, the earliest 

 conditions of the adventitious buds mav be seen in the form 

 oi a disk surrounded by an annular furrow and having a 

 slight protuberance at its middle point which represents the 

 apex of the new axis in process of formation. Somewhat 

 later, other protuberances, being the rudiments of fronds, 

 are seen, arranged in a circle round the central one (PI. 

 XXVII, fig. 5). Whilst on the mother- plant the new 

 shoot begins to send forth roots independently (PI. XXVII, 

 fig. 6). The vascular bundles which pass to it from the 

 vascular bundles of the frond on which it is produced, 

 unite at its place of attachment so as to form a closed 

 ring from which their distribution in knots answering to 

 the insertions of the fronds commences (PI. XXVII, fig. 7). 

 Such adventitious buds are formed on vigorous plants in 

 fertile habitats at about every twelfth frond, and much more 

 frequently in plants growing in dry situations.* 



Aspidium spinidosum comports itself in all its parts like 

 Aspidium filix-mas. The adventitious buds are here met 

 with very near the base of the stipes. The scales bear at 

 their apices, and frequently also on the teeth of the margin, 

 very swollen, oval, or pear-shaped cells with mucilaginous 

 contents ; a phenomenon which is also seen in Aspidium 

 Oreopteris, Asplenium filix-femina, Struthiopteris germanica 

 and other ferns. 



Asplenium filix-femina; Asplenium Bellangeri; Struthiop- 

 teris germanica ; JVep/trolepis imdulata ; Nephrolepis splen- 

 dens. The above-named ferns agree entirely in the principal 

 features of vegetation, viz., in the form and mode of multi- 

 plication of the cells of the terminal bud ; in the position of 

 the frond-cells of the first degree with regard to the apical 

 cell of the terminal bud ; and in the arrangement of the 



* It is probable that Schleiden had these buds in view when he spoke of 

 this fern as having axillary buds (' Grundziige ' 2 Aufi., vol. ii, p. 87), which 

 in Aspidium filix-mas, as in all European ferns, are absolutely unknown. 



