1 88 THE ORCHID REVIEW. 



6. True specific characters are more easy to follow in a complex 

 hybrid than varietal, or even racial ones. 



7. In isolated Orchid species the pedigree of pure specific characters 

 is known to have been the same for many generations, thus being less 

 liable to reversion than mere racial or varietal characters, whose origin is 

 comparatively recent. 



The author then goes on to explain that when two distinct species of 

 Orchids of the same genus are crossed together, the resulting hybrid is, 

 as a whole, fairly intermediate between the two parents. But if, as in 

 Mendel's system, each pair of specific characters be examined separately in 

 a number of plants, it is found that the character of each species is, as a 

 rule, inherited in different degrees by the hybrids. For example, Paphio- 

 pedilum insigne has well defined spots on the dorsal sepal, which are 

 absent in P. Spicerianum, while in P. X Leeanum, the hybrid between 

 them, a few forms may be found almost as much spotted as in P. insigne ; 

 a few others (even from the same capsule), as spotless as P. Spicerianum; 

 a third moiety will be truly intermediate, showing spots reduced in size 

 and number ; while the great majority will vary on either side of the 

 truly intermediate form, right up to the two extremes, making a perfect 

 series. This rule may be extended to other characters and other hybrids. 



In order to avoid ambiguity it is proposed to call all forms which deviate 

 25 per cent, or less from either parent "specific," and they are marked 

 ■" A " and " a," while the remainder (varying less than 25 per cent from the 

 mean) are called "intermediate," and marked " Aa." In the case of P. X 

 Leeanum, a large number of hybrids were analysed, giving in all 492 

 characters, 248 of which were "specifics" and 244 "intermediates." And 

 the case is put thus :— " Now, if P. Spicerianum = A, and P. insigne = a, 

 the precise formula in this case works out as 127 A + 244 Aa + 121 a, 

 which, considering the small numbers used, is a close approximation to 

 A 4- a + Aa + a, which agrees with Mendel's observations in the case of 



The result of analysing upwards of no hybrids of different genera agrees 

 substantially with the preceding, but the author proposes to show in a 

 subsequent paper that "this formula of Mendel, though useful as a 

 working formula for hybrids of a certain ancestry, has its limitations ; and 

 that Mendel's theory in explanation of that formula cannot generally be 

 maintained with Orchid hybrids," or, in other words, that " Mendel's 

 formula is not a general law, but simply a particular formula for a 

 particular group of hybrids and crosses." This second paper will be 

 awaited with interest. 



The second paper is a " List of Orchids used in the fertilization of 

 Hybrids which have received either First-class Certificates or Awards of 



