398 HOFMEISTER, ON 



In the mode of cell-multiplication, the succession of the 

 shoots, and the development of the leaves, Lycopodium* comes 

 much nearer to the Polypodiaceae (for instance to Aspidium 

 fliv-mas) than to Selaginella. The terminal bud which is a 

 conical wart, extends somewhat beyond the place of origin of 

 the youngest leaf. The division of its apical cell, as well as 

 the multiplication of the cells of the second degree, resembles 

 the same process in Aspidium. The leaf appears to be 

 formed by the multiplication of a single cell of the circum- 

 ference of the terminal bud. It grows in length by divi- 

 sion of an apical cell by septa inclined alternately towards 

 the upper and the under surface of the leaf. Here also it 

 is easily seen that the cells of the base continue to divide 

 long after the multiplication of the cells of the tip of the 

 leaf has ceased. Ramifications of the stem occur by the 

 forking of the terminal bud above the place of origin of 

 the youngest leaf.f The growth of the roots exactly re- 

 sembles that of the adventitious roots of the Polypodiacese, 

 the Equisetaceae, and the Pilularise. 



Psilotum triquetrum is exactly like the Selaginellae in the 

 mode of forking its terminal buds. This plant also re- 

 sembles Selaginella viticulosa, and still more so S. corclifolia, 

 in the relation of the annual shoots to the buried perennial 

 stem. 



The growth of the stem of Psilotum results from the 

 repeated division of a single apical cell by means of septa 

 inclined alternately in different directions. The growth of 

 the leaves in the first stages of development resembles that 

 of Lycopodium. Afterwards a forking of the tip of the 

 leaf takes place. 



The reproduction of those Lycopodiacese which bear 

 powdery spores of one kind only is still a mystery. Re- 

 peated sowings of the spores of Lycopodium clavatum, 

 L. inundatum, and of Selago, have yielded me no results, but 

 I have lately often observed that in spores of Lycopodium 

 Selayo, which had been sown for from three to five months, 

 numerous small spherical cells had been formed, similar to 



* I have particularly examined Lycopodium inundatum. 



f Compare Nageli, ' Zeitschr. f. Botanik/ Parts 3 & 4, PL v, fig. 1. 



