OF PH^ENOGAMOUS PLANTS. 



being in organic connection with their parent stem, do not 

 usually produce roots ; but when placed in equally favorable 

 conditions for it, i. e. on or in the soil, they may strike root as 

 freely as does the original stem. 



15. An incipient stem or branch, with its rudimentary leaves, 

 is a BUD. The normal situation of a bud is in the axil of a leaf 

 (axillary} , the development giving rise to branches ; or else at 

 the apex of an axis (terminal), where there can be only one, the 

 development of which continues that axis. 1 



16. As branches are repetitions and in one sense progeiry of 

 the stern which bears them, so the serial similar parts or leaf- 

 bearing portions of a simple stern are repeti- 

 tions, or in a like sense progeny, each of the 



preceding one from which it grew. The 

 simple-stemmed plant is made up of a series 

 of such growths, each from the summit of 

 its predecessor ; the branched plant, of ad- 

 ditional series, laterally developed, from ax- 

 illary buds. These ultimate similar parts into 

 which a plant may thus be analyzed, and 

 which are endowed with or may produce all 

 the fundamental organs of vegetation, were by 

 Gaudichaud called PHYTONS. But phyton, 

 being the common Greek name for plant, was 

 not a happily chosen appellation for plant- 

 elements, or homologous plant-units. A better 

 term for them is PHYTOMERA (cpvrov, plant, 

 ftsQo^, part), equivalent to plant-parts, --the 

 structures which, produced in a series, make 

 up a plant of the higher grade. In English, 

 the singular may be shortened to PHYTOMER. 



17. This theoretical conception of the organic 

 composition of the plant is practically impor- 

 tant to the correct understanding of morpho- 

 logical botany. The diagram, Fig. 1, serves 

 to represent the organic elements, or phi/fomera, 

 in a simple case, such as that of a growing 

 plant of Indian Corn, or other Grass. Here 



1 Bifurcation by the division of a terminal bud into two, as in Acrogenous 

 Cryptogams, is supposed by some to occur, even normally, in some Plueno- 

 gams, especially in certain forms of inflorescence ; but this has never been 

 convincingly made out. 



FIG. 1. Diagram of a simple-stemmed plant, exhibiting the similar parts, or 

 phytomera, a to h, of which it is composed. 



