MENDEL'S PRINCIPLES APPLIED TO ORCHID HYBRIDS. 621 



(6) In I the ground-colour, except the apex, is regularly covered with 

 spots, which are brown on the green and purple on the white areas. 



(c) In B the ground-colour, except the apex and margins, is 

 irregularly covered with purple-black blotches, more or less confluent. 



(d) In SI the ground-colour is partly covered with dots, brown on the 

 green and purple on the white areas ; these dots vary in size and number 

 as they approach either parent, S or I. 



(e) In BS the ground-colour, except the apex and margins, is covered 

 with stripes and mottlings more or less suffused, purple-black on the 

 green and purple on the white areas ; these markings vary in size and 

 number as they approach either parent, B or S. 



(/) In BI the ground-colour, except the apex and margins, is 

 regularly covered with large spots, black-brown on the green and dark 

 purple on the white areas ; these spots vary in size and shape as they 

 approach either parent, B or I. 



An analysis of the 49 hybrids SI x B, obtained by careful com- 

 parison with the above forms in regard to the single character of the 

 markings on the ground-colour of the dorsal sepal, gives : — 



26 BS, comparable with the various forms of P. x Calypso (BS), 

 and 23 BI, comparable with the various forms of P. x Schlesingerianum 

 (BI). In no case is there among the forty- nine hybrids a form 

 approaching either SI or BSI. 



As regards this single character, therefore, the facts appear to be in 

 accordance with Mendel's theory. 



3. The Median Band, Bar, or Stripe of the Dorsal Sepal. 



(a) In S this is highly developed and clear-cut, being a solid bar of 

 dark purple extending from base to apex. 



(b) In I it is quite absent. 



(c) In B it is somewhat obscure, generally irregular in outline and 

 mostly confined to the upper middle of the dorsal sepal, and rarely 

 extends up to the extreme apex ; in colour it is purple-black, with suffused 

 margins of purple. 



(d) In SI, when present, it is usually faint, taking the form of dotted 

 or suffused lines. 



(e) In BS it is well developed from base to apex, and quite inter- 

 mediate in size and colour between B and S. 



(/) In BI it is either quite absent or is represented faintly by linear 

 spots of purple-black. 



An analysis of the 49 hybrids of SI x B, obtained by careful com- 

 parison with the above forms in regard to the character of the median 

 band of the dorsal sepal, gives : — 



30 BS, comparable with the various forms of P. x Calypso (BS), 

 and 19 BI, comparable with the various forms of P. x Schlesingerianum 

 (BI), there being no case of either BSI or SI. 



As regards this single character, therefore, the facts are apparently in 

 accordance with Mendel's theory. 



For the sake of clearness and comparison, I have put into tabular 



