38 GRXKl.'Al. IIEVIKW OK TIIK ORCIUPE.K. 



possibly glean some hints us to the most promising- directions in 

 which to prosecute their labours, and the students of orchid structure 

 may be interested in observing that these protean aberrations ai-e really 

 consistent with law and order. Of course a knowledge of the normal 

 conformation is the first essential to an understanding of the abnormal 

 condition, but if the reader has paid attention to the numerous 

 illustrations given in the foregoing pages with the accompanying- 

 description, and which should be supplemented by studying and 

 comparing every orchid flower that comes in his way, he will 

 experience no difficulty whatever in comprehending what follows. 



As already pointed out, an orchid flower consists of fifteen parts, 

 viz., three sepals and three petals alternating with them, hut one petal 

 is generally so very different in appearance from the other two as to be 

 called by a separate name, the labellum or lip ; the sepals and petals 

 collectively constitute ihe perianth. In the centre of the flower 

 surrounded by the perianth is the column which is typically a com- 

 bination of six stamens and three styles, but in the adult state only 

 some of these parts are visible. Of the six stamens, of which traces 

 may be usually seen in the anatomy of the flower and especially in 

 the development and distribution of the vessels, five are arrested in 

 their development, come to nothing or are represented by mere rudiments. 

 One only reaches maturity in all the tribes except Cypripedium. In 

 that genus four of the stamens are abortive and two are fully 

 developed, and in the little known genus Xeuwiedia three are abortive 

 and three are developed. 



The relative positions of these fifteen parts are indicated in the 

 diagram in page 35. Bearing these in mind it is in general easy to 

 group the deviations that are met with into certain principal 

 categories ; thus the parts of the flower taken collectively may be 

 altered : — 



I. In number, either by arrest cf growth (defect), or by excess 

 (increase). The defect or the excess may ho in one series or whorl, 

 or in more than one. 



II. The change may show itself in the union, or in the disunion 

 of parts. In the former case the union is generally congenital, and 

 the term concresfence or inseparation is made use of to imply that the 

 so-called union is really due to the lack of sej^aration rather than to the 

 union of previously isolated parts. The nnion or the disunion may of 

 course take place between members of the same or of different floral 

 whorls. 



III. Another very frequent change is due to irregular or dispropor- 

 tionate growth ; of this, in a normal oichid flower, the labellum is a 

 notable example. 



