42 



GENERAL REVIEW OF THE ORCHIDE^R. 



lateral segments are subject to the same changes as to union and 

 disunion (dialysis) and reduction as the sepals. 



One very common change affecting the perianth as a whole may 

 here be mentioned, and that is, a reduction in the number of parts 

 in each whorl, so that instead of there being three sepals in one 

 whorl alternating with three petals in the next, there are Init two sepals, 



Fig. 4. Regular pcloi-ia in T.a'lict pmnila. In the left hand tlowpr the lip scarcely differs from the lateral petals. 



(From the Gardeners' ChrnnU-k.) 



and these are crossed at right angles by a pair of i^etals. An illustration 

 of this in Cattleya (jnttata is shown in Fig. 2. (This change is almost 

 normal in the two lowermost flow^ers of Graivmafoplujllnm Fenzlianum 

 var. Measuresiamim.) 



The lip with its gorgeous colouring and singuhir form attracts the 

 attention of the cultivator, whilst its position, its structure, its infinite 



