1 14 M. Miiller on the Development of the Lycoi^odiacese. 



The third investigator, whose opinions on this subject I have 

 become acquainted with, is Schleiden. He declares himself most 

 decidedly in favour of MohFs view, and says (Grundziige, ed. 1. 

 part ii. 81), " that the spore-fruits are special modifications of the 

 parenchyma of the leaf, has been shown by Mohl as clearly as was 

 possible without tracing the development. This however affords 

 the same results/-' From this last sentence we may guess that 

 Schleiden had founded his very definite statement on an exami- 

 nation of the development. This however is not to be found in 

 his earlier writings, and it is therefore very much to be regretted 

 that this author has not given us a more detailed account of it ! 



How far my own investigations agree with the foregoing opi- 

 nions, will best be seen after 1 have given the history of the 

 development so far as I have arrived at any conclusions about it ; 

 these I hope however may solve the questions above stated. 



1. The spike (spica nonnullor., amenta et strobilus. Spring.). 



The inflorescence of Lycopodia is always to be regarded as a 

 spike : the peduncles of the fruit may be abbreviated and the 

 leaves be thus brought closer together, in which case the cha- 

 racter of the spike appears most distinctly, or the leaves may re- 

 main in their original position. In this latter case the fruit is 

 said to be scattered on the stem. It will be evident that 1 here 

 of course only speak of the genera Lycopodium, Selaginella and 

 Phylloglossum. 



The form of the spike naturally depends upon the arrange- 

 ment of the leaves of the species, and therefore has usually no 

 remarkable differences from, the preceding whorls of leaves. In 

 Selaginella alone it is regularly altered in such a manner, that 

 while the leaves of the compressed branches, in four rows, — two 

 above and two below, — are distant and of two forms, the leaves of 

 the spike are densely crowded and thus form a four-sided spike 

 on the round axis; for the little uniform leaflets are strongly 

 keeled, overlap one another regularly, and the keel is thus dis- 

 played at a prominent line on the spike (PI. IV. fig. 13). Four 

 such lines occur normally, and the four-sided form is thus pro- 

 duced as the fruit-leaves are compressed so as to form an angle. 

 The spike of Lycopodium denticulaium is of this form. Two cir- 

 cumstances have an important influence over its perfect develop- 

 ment. If the axis of the branch does not become attached to 

 the earth by its roots — and this is often the case in plants raised 

 in pots — the spikelet of the branch which has not attached itself 

 by rooting is manifestly retarded in its development, and often 

 to such an extent that it scarcely visibly projects beyond the 

 leaves ; but on the other hand, when the branches always root, 

 the spikelet acquires a considerable height. 



On this now occur oophoridia and antheridia. The character 



