34 M. Muller on the Development of the Lycopodiacese. 



fectly round until a later period, when it gradually produces a 

 number of new cells upon the base. This however takes place 

 but slowly, and it is seldom that the whole contents of the spore 

 become completely transformed into cells before the plant has 

 attained a condition in which its self-sustaining power has be- 

 come tolerably evident. Considered in connection with the plant, 

 the " germ " in its perfect condition is pear-shaped, a neck being 

 formed where it breaks through, and rises from the spore (fig.4 «). 

 At a later period it disappears, apparently through decomposi- 

 tion. 



2. The rootlet. This first appears, as I have already said, 

 under the form of a little conical process (fig. 1). Its substance 

 originally consists of an apparently structureless, undeveloped 

 deposit of roundish granules which appear of a somewhat reddish 

 colour. The apex however of the radicle is more transparent. 

 It soon grows longer, forms parenchymatous, elongated tissue, 

 and many of its epidermal cells become radicle fibrils. The 

 inferior extremity still remains, as at first, more transparent, i. e. 

 having the reddish substance and the brighter point, which is 

 indeed the condition of newly-formed parts generally. I have 

 never been able to find any little spongy investment upon this 

 end, and I therefore know not what Bischoif alluded to under 

 this character. I have seen a number of radicles in all stages, 

 and have carefully examined them under the microscope ; but an 

 organ of this kind, such as we find in Lemna, never presented 

 itself to me. As to the vessels, which the root subsequently ex- 

 hibits, they are formed after those of the stem. The growth of 

 the root generally is slower than that of the last-named organ. 



The subsequent course of development of the radicle is an 

 elongation and dichotomous ramification. As soon as the plant 

 has become more independent, several roots are developed at the 

 base of the stem_, and these present characters exactly similar to 

 those of the first. Like this they originate from the extension of 

 the ^^ germ,^^ and by their frequent occurrence on the same point 

 of attachment they render it very doubtful whether we ought to 

 consider the root first developed as a chief root [Hauptwurzel) as 

 Schleidendoes*. It is indistinguishable from those subsequently 

 produced, and only has the advantage over them in the fact that 

 it is the first formed and is on a level with (its axis correspond- 

 ing with that of) the stem. The only question is therefore how 

 much importance is to be attached to this last circumstance. 



The radicle fibrils subsequently appearing upon the foliaceous 

 branches do not differ from these roots in their structure and 

 development. But these cannot be spoken of until we come to 

 the formation of branches. 



* Griindz'jge, ed. 1. ii. 79. 



