260 THE ORCHID REVIEW. [SEPTEMBER, 1906. 
grown in great numbers and close together, affording the most favourable 
conditions for reciprocal fertilisation between the varieties present and the 
species itself. The probability of this is supported by the fact that among 
the great array of variable forms solitary examples are always found, which 
in one character or another remains constant, if only foreign influence is 
carefully excluded. These forms behave precisely as do those that are 
_ known to be members of the compound hybrid series.” 
Mendel thus showed that segregation was not only a quite familiar 
phenomenon, but also that in some cases it did not occur, and he formed his 
conclusions accordingly. His paper passed almost unnoticed for thirty 
years, when suddenly it was brought into the light, and his results with peas 
were confirmed by other observers. The subsequent extensions of the 
Mendelian conceptions are treated in the work under review, and some of 
them would probably have startled Mendel himself, could he have seen 
them. 
Examples drawn from Orchidology are not numerous, and are cited from 
other sources. Several genera are said to show Mendelian Inheritance of 
Colour character, and the facts are said to be exactly comparable with sweet- 
peas. The cases mentioned are albino Cypripediums and Cattleyas. Of 
the former it is stated that C. callosum Sandere xX C. bellatulum album 
gives all coloured offspring, and the same with C. Lawrenceanum Hyeanum 
Xx C. bellatulum album, but, on the other hand, C. Lawrenceanum Hyeanum 
x callosum Sanderz gives offspring all albinos, and the following conclusion 
is reached. ‘‘ If therefore we suppose that bellatulum album is carrying one 
of the complimentary factors, say C, and that the other factor R is present in 
callosum Sanderz and in Lawrenceanum Hyeanum, the results are correctly 
and consistently represented.’ In this connection we may recall the case of 
C. bellatulum album  X C. insigne Sanderz, which failed to give albinos, as 
we shewed over a year ago (O.R., xvi. p. 105, fig. 18). Again we read: “As 
regards the behaviour of the pure types, however, there is one occurrence to 
be recorded which cannot be explained. . . . Lawrenceanum Hyeanum, 
when selfed, gave 14 albinos, but in addition one coloured plant, which 
Mr. Cookson tells me cannot be thought to have resulted from error. Such 
an occurrence is as yet unaccountable.’’ But we do not see why reversion 
to the normal should be unaccountable. 
The case of albino Cattleyas may be summarised thus: “‘C. Mossiz 
Wageneri crossed with both C. Gaskelliana alba and with C. intermedia 
alba gave all albinos, but when the two latter were united with C. Schroederz 
alba and C. Harrisoniana alba the hybrids were all coloured. But whenC. 
Gaskelliana alba was crossed with C. Warneri alba both albinos and coloured 
forms resulted. Wedonot think this quite comparable with the case of the 
sweet-peas cited, where the intercrossing of two whites gave a. purple, “ in 
