324 M. Pringsheim on the Pro-Embryos of the Cnarro. 



circle of leaves, but that it is the apex of a distinct structure 

 following a peculiar mode of growth, and that it is only under 

 this leaf-like apex, and at a later period, that the first normal 

 bud is produced and developed into a normal barked or naked- 

 footed twig, which is only distinguished from other twigs of 

 Cham by its basal node producing a few leaves which remain in 

 a rudimentary state of development. 



Now, it is from these little leaves coinciding in a circle with 

 the end of that independent organ to which I give the name of 

 " progerm of the twig" that it appears as if the twig above this 

 whorl was the direct continuation of the joints below it. 



The recognition of this gets rid of all the contradictions and 

 abnormal appearances which strike us in the lower joints and 

 the first whorls of these twigs so long as we start from the false 

 assumption that the structure which I indicate as the apex of 

 the progerm of the twig is the excessively developed oldest leaf 

 of the first whorl ; for neither the development of this pro- 

 germinal apex, nor the form of its terminal cell, nor, lastly, the 

 directions of the currents in its cells agree with the normal 

 condition of the parts of a leaf. 



The full significance of this progerm of the twig only becomes 

 evident, however, by the comparative examination of the germi- 

 nating plant. 



The considerable deviations from the normal structure of the 

 joints and nodes which are observed in the first joints and nodes 

 of germinating Chara> arc most simply explained by the same 

 processes of formation which I have shown to occur in the pro- 

 germs of the twigs. 



The germination of the spore also commences with the forma- 

 tion of an independent organ following a law of growth peculiar 

 to itself — a progerm, from the leafless nodes of which the leafy 

 twigs sprout forth. 



The progerms formed by the spore resemble in every respect 

 the progerms of the twigs produced on the older nodes of plants 

 which have passed the winter. They reach from the spore to 

 the first whorl of leaves, and terminate here with the same ex- 

 cessively developed structure apparently belonging to the whorl, 

 which has been regarded sometimes, as by the older observers, 

 as the apex of the growing main stem, and sometimes, as by 

 more recent investigators, as the first, disproportionately deve- 

 loped leaf of the first whorl. 



It is, however, as already stated, neither the one nor the 

 other, but the apex of a leafless provisional structure incapable 

 of further development; and the leaflets in its vicinity, with which 

 it apparently coincides to form a whorl, are, as in the progerms 

 of the twigs, the rudimentary leaves of the basal node of the 



