146 POGONIA OPHIOGLOSSOIDES. SNAKE-MOUTH. 



Great Architect had not got far beyond the foundations of his 

 work in makino- a PocoJiia. The vec:etative force seems feeble, 

 and spends itself in often-repeated attempts ; hence, small leaves 

 and insis^nificant flowers are scattered all aloni^ the stem. But 

 in P. verticillata the force exercised is evidently greater, not 

 only in amount, but also in degree, and its action is more con- 

 centrated. The stem, therefore, instead of slowly elongating, 

 and sending out a leaf and a flower here and there, rapidly 

 draws in its spiral coils, thus producing only a verticil or whorl 

 of leaves, and annihilating all tendency to flower in the axils ; 

 after which it makes another growth, and then another sudden 

 arrest and coil, resulting in a large, single flower. Coming 

 now to P. opJiioglossoidcs, we find that the acting force was 

 intermediate in intensity. .Having coiled up the primordial 

 leaves to form the flower-stem, the force was not powerful 

 enough to arrest the formation of the leaves suddenly, and it 

 therefore still left them somewhat scattered. Of the three leaves 

 thus produced the lowermost is little more than a sheathing 

 scale. The next or largest one shows by the groove down the 

 stem opposite, as seen in our illustration, how very near it came 

 to diverging still more than it actually does from the interior 

 leaves, out of which the stem is formed ; and the upper one, by 

 its greatly reduced size, reveals the fact that the force employed 

 in arresting the elongating growth, and in working up all the 

 separate parts into a flower, is now in active operation. Thus 

 we see how an exceedingly beautiful structure is built up from 

 a few rough and simple materials. 



In distinguishing the genera of Orchids, the relative differ, 

 ences in the sizes and forms of sepals and petals are taken into 

 consideration, as well as the relative forms of the petals them- 

 selves. The lip is often very characteristic, and almost alone 

 will enable the botanist to build a genus on it. Our present 

 plant was regarded by Linnceus as an ArctJmsa, and as such it 

 is described in all old works ; but in this last-named genus, the 

 sepals and petals are united at the base, while in Pogonia they 



