352 DR. M. T. MASTEES ON A DOUBLE-FLOWEBED ORCHIS. 



* 



here he remarked that if in this whorl one segment were absent, 

 it was precisely the one which in the natural flower is deficient. 

 In the untwisted flower this would be posterior; but in the ordinary 

 blossom it would be anterior, as shown in ^ 3 (PL XI. ii.)- 



The fifth whorl would correspond to tlie stigmas (S, PI. XI. ii.); 

 and here, again, it must be noted that this whorl is rarely com- 

 plete, but is most generally represented by one segment, placed 

 anteriorly (in the untwisted flow^er), and thus corresponding to 

 the single stigma always present in Orchids, and Avhich in the 

 reversed flowers is placed posteriorly. 



So far, then, the first five Avhorls of these double Orchids coin- 

 cide exactly in position with the whorls of the theoretical Orchs- 

 flower ; but, as happens in many other double flowers, the stamens 

 and pistils are represented by petaloid organs. 



The sixth and seventh whorls, on this view, would be accoimted 

 for by a process of multiplication or of increased numerical deve- 

 lopment, such as is so common in double flowers. 



Hence, then, I am disposed to regard these flowers as doubled, 

 first, by the substitution of petaloid organs for stamens and 

 pistils, the several parts not becoming fused one with the other, 

 and, next, by an increased development of perianthial segments 

 in the centre of the flower. 



The other mode of explaining the conformation of these flowers 

 is that afi'orded by median prolification ; and this is the explana- 

 tion adopted by Dr. Moore ; but the perfect mode in which the 

 members of one series alternate with those of adjacent rows, and 

 their strict conformity in position to the organs of a normal 

 OreZ'/^-flower, induce me to think that there is no median pro- 

 lification, so far as the primary flo\vers are concerned. More- 

 over, if these flowers were the subjects of median prolification, 

 there would be an internode separating one flower from another, 

 as well as traces of bracts and of ovaries ; but none of these were 

 to be seen. With reference to this point I had the advantage of 

 comparing these specimens with some flowers of Orchis pyrami- 

 dalis, also forwarded by Dr. Moore, and which were really pro- 

 lified. These have been previously brought under the notice oi 

 the Society*. 



I must now mention the adventitious buds which were found 

 in the axils of some or all the members of the six inner whorls ot 

 the primary flower, the outermost series having presented none 

 of these axillary developments. The most completely formed ot 



Journal of the Linnean Society, (Botany) vol.viii. p. 211. 



