39 



3- The reverse of albinism — cases in which normally white or 

 greenish flowers develop color. This variation occurs in two 

 directions. Normally white or greenish flowers may become more 

 or less flushed with pink, as in Dicentra Cucullaria, Anemone 

 quinquefolia, Ruhiis alleghaniensis , Circaea latifolia and Daucus 

 Car Ota, or even deep red, as I have seen them in Vacciniiim 

 vacillans, or purple, as in Daucus Carota. Or normally white 

 flowers may develop a cream-colored pigmentation. I have 

 seen but one case of this, in Hahenaria hlephariglottis . Similar 

 forms of this species have been regarded as hybrids with H. 

 ciliaris; but my specimens were found at South Windsor, Conn., 

 where the latter is wholly unknown. 



4. Blue or purple to pink, as in Trichostema dichotomum, Aster 

 novae-angliae, Lupinus perennis, Hepatica americana, Linaria 

 canadensis, and Prunella vulgaris. The reverse change, from 

 pink to blue, does not seem to take place in our region and per- 

 haps not in nature — the impossibility of a blue rose or a blue 

 orchid is proverbial. In certain Boraginaceae, however, as is 

 well known, the bud is pink and the mature corolla blue in the 

 same flower, and in Desmodium marilandicum and related species 

 the magenta flowers take on when withering a peculiar greenish 

 blue. 



5. Crimson or scarlet to yellow or vice-versa. Lilium philadel- 

 phicum, L. canadense, Castilleja coccinea, Trillium erecttim, Coral- 

 lorrhiza maculata and the red or yellow portions of the flower in 

 Aquilegia canadensis and Pedicularis canadensis are examples. 

 This change takes place in both directions : Lilium philadelphicum 

 has a beautiful clear yellow form and L. canadense a red one 

 rather common in some localities. 



If one carries curiosity further and asks what causes color- 

 forms and by what process they arise, his quest for a satisfactory 

 answer is likely to be long. One thing seems wholly probable, 

 almost certain — that they are not produced by external condi- 

 tions. They occur ordinarily in the closest association with the 

 typical forms of their species. I once thought indeed, that I 

 had detected a difference in the specific acidity of the soils in 

 which certain color variants and the typical forms near by grew, 

 but the difference held only for the first three or four cases tested : 

 in the next three or four it broke down. Whatever the cause 

 may be, it is apparently something internal and physiological, 



